Great advice! I'll add:
1) You cannot start a 529 account at the moment the child is born because it takes several months to obtain a social security number. The time around birth is, unfortunately, exactly the emotion-driven moment when friends and relatives would be MOST likely to give large sums. Get around this by setting up a temporary savings account that people can write checks to and that will be moved into the child's 529 as soon as it can be set up. Don't be shy about explicitly soliciting donations. Use an online service like Venmo for the younger crowd and accept checks from the older crowd. When people ask you if you need anything, hand them a small printout you've made with deposit instructions and an explanation that the account will go to kiddo's future 529. When the 529 is finally established, let everyone know again. Include a handout in all birthday invitations. These little steps could easily raise $5k-10k around birth time, which will be several times that amount in 18-20 years.
2) Start couples counseling. Any fracture, any incompatibility, any passive-aggressive tendency, any over-reliance on sarcasm, any irritation or bad habit becomes 3x as bad when you're sleep deprived for weeks, when you've lost your autonomy over your own time, when you physically hurt, when you're stressed about the latest ear infection or diaper rash, when it's been months since your last episode of intimacy, and when you just got pooped on because your SO was too exhausted to take their turn. Even if you seem to have nothing but first world problems now, address them before they become fights. See if you can agree in advance on tentative plans for things like housecleaning, grocery runs, taking shifts at night so you each get at least a half-night's sleep, etc. Even if when you end up having to break the plans later, it's better to start with a plan.
3) Fix your stuff. Don't go into the most intense year of your life with appliances or cars that are on their last legs, or home repair items that could blow up on you. How old is your HVAC and water heater? Do you need a new roof? Etc. You won't have time to deal with this stuff in the near future. You'll be challenged to DIY anything. If you have toys like motorcycles, ATVs, or boats, sell them before the gasoline rots. You won't pick up these activities again for at least 4 years.
4) Read quality books on parenting. Spoiler alert: much of what you think you know is not scientifically supported. Also see #10.
5) Line up an in-network pediatrician in advance.
6) Be prepared and have discussions - perhaps with your counselor - about how you hope to handle things if your child is born with a disability. Hope for the best but be prepared so that you don't go into analysis paralysis or fall back on bad behaviors and dysfunctional attitudes if it happens. Your disabled, premature, or medically frail child will need you to be on your A-game. Rise to the challenge whether you need to or not.
7) Drop your time-wasting habits. If you are used to watching an hour of TV a night, or if your phone says you spend 3h per day on it, maybe dial back in preparation for a time when these filler activities are no longer in the budget. One of the most dysfunctional things a new parent can do is feel like they are still entitled to their time-wasting activities when they aren't getting enough sleep and when their SO sees they are not doing their half of the work*. It's even worse when one person is depriving the other of sleep! That's the highway to fight city. (*Note: neither of you will do your half of the work)
8) Set up a baby registry and let family, friends, neighbors, and co-workers know about it.
9) Expect to feel social isolation. Try to keep up your social life through the pregnancy, and then let people know they are welcome to come over for visits with the newborn. You won't feel like reaching out to them, so directly let them know you expect them to reach out to you.
10) DO NOT accept ANY information about your baby's health from social media. Social media is a 100% INVALID source for info on vaccines, childhood illnesses, diet, developmental milestones, or really anything else. Maybe there's some truth out there, but so what? The landscape is a minefield of misinformation, and you might not recognize it all. Parents are literally harming their kids based on clickbait from "influencers". Trust your pediatrician, your public health office, and legitimate books such as those endorsed by the American Academy of Pediatrics. Likewise, friends, religious leaders, celebrities, Dr. Fucking Oz, neighbors, podcasters, and lots of other people without "pediatrician," "OB-GYN," or "child psychologist" on their business cards will have opinions on technical subjects and you should just nod your head, say "that's nice," and ignore it. Even among those who do have the business cards, maybe consider factors like where they went to school, whether they earn their money helping patients or selling media, whether their views are consensus, etc.
11) Commit now to certain values. Examples: We will not have an "electronic babysitter" for our kid. We will not feed our kid processed foods or junk foods. We will not spank. We will read to them every night it is possible to do so, even if we don't feel great. We will contribute 1% of our salary to their 529. We are an exercising family despite having a baby, etc. With our young one, we started reading two bedtime stories per night before they were 1. That little ritual made them an absolute bookworm, who at age 8 has been knocking out 400-500 pages of youth literature a day this summer. Similarly we committed to healthy foods and have an extremely healthy and athletic kid. However we failed to commit to the value of minimizing screen time, so now that adventures like family bike rides are possible, it's hard to tear them away from Roblox. You lie in the bed you make, and your kid will mimic both your good habits and your bad habits!
12) Obviously, if you smoke or have a drinking habit, NOW is the time to stop. It may take years to extinguish these behaviors but the outcome will be a healthier child and a stronger family. Engage with a counselor now, not after years of failing. Expect setbacks, but GET IT DONE.
13) Consider starting to try for a kid now, especially if you think you might want 2. The process could take a while, so think about how you will approach "advanced maternal age", which is only 35. After this point, the risk of complications and birth defects increases at a significantly faster pace. If you might want 2 or 3 kids and each pregnancy is 2-3 years apart, and you're not starting for a while... time will run out before you know it.
14) Get on a daycare waiting list late in the pregnancy. Shop around. Facilities with no TV are usually the best. The established scientific consensus is that early childhood education boosts academic scores later in life, so consider that when one parent decides after the birth that they want to stay home. In our case, the urge to have a stay-at-home parent was tempered by this knowledge, and by the fact that quality childcare is relatively cheap where we live.
