My DH and I graduated in 2014, and we purposefully negotiated with our employers to start later. We graduated in early May, and DH started working mid-June and I had a start date of mid-July.
We spent that month backpacking and camping in 8 national parks, and to this day that was the most fantastic trip we have taken. 5 weeks of having the time of our lives exploring gorgeous landscapes, meeting interesting people, and learning to live out of our tiny car. Most employers will be perfectly fine to delay your start date unless you are entering a rotational program or something that has a hard start date (some larger companies do this, and as a side note, highly recommend rotational programs for your first job out of college if that works out for you).
I think we spent maybe $3k for 5 weeks for the two of us, including park passes, food, gas, etc. We spent the months before the trip looking out for deals on equipment.
This isn't a post-graduation wish, I actually wish I had kept up my exercise routine in college. I was in sports all year during high school but didn't continue that in college, and my motivation for working out without a group isn't all that high. I still struggle to remember to do my workouts because I refuse to pay for a gym membership/classes and I'm healthy and in pretty good shape, but I miss my muscles/fitness. So I guess I would say set a workout schedule/plan and commit to it. It has improved lately once I made a weekly schedule, where I actually chart out the hours I'm at work, making dinner, grocery shopping, watching TV, reading, hobbies, etc. Scheduling an hour after I get home from work every day has helped a lot--I find if my butt hits the couch, I have a hard time getting back up, so I have to get my workout in before settling in for the evening.
I'd also suggest figuring out better sleep hygiene once you graduate. College is horrendous on sleep habits and I remember after graduating that I struggled to fall into a regular sleep pattern now that I had to be up at the same time every day. So as part of my weekly schedule, I have an hour of reading before bedtime so I'm not fiddling around on my laptop, mindlessly watching tv, scrolling fb, etc right before I need to be asleep.