In the last two years we have done two rather similar routes. In 2017 we drove from Banff/Jasper down to Yellowstone, then took the Continental Divide through Colorado, hopped West and did Ouray, then Grand Canyon.
Earlier that year, we did 3.5 weeks going 3000 miles from Phoenix to Cabo San Lucas and back via motorcycle (myself and my wife on the back). We camped on the beach every other night but stayed in a hotel in Cabo for a few days for R&R.
In May, it may start getting a bit hot the further south you go to camp. You’ll need to play it by ear, but don’t hesitate to get a hotel (they’re cheap) because nothing is more miserable, to me, then trying to tough out camping when it’s just way too hot. For reference, we went in February and even then, towards the southern part it was getting a bit warm to enjoy camping.
You’ll want a GPS that doesn’t need cell service. I used “OsmAndMaps” on my iPhone and it worked fine. No turn by turn but works everywhere. I’d honestly suggest an InReach or Spot type satellite phone/tracker. It gets pretty desolate out there unless you stick on the main highways (which you won’t want). Gas stations can be spread out, so I’d bring some extra gas.
There’s a AAA Baja Map thats the best you can find. If you can’t find it, PM me.
Go on advrider.com and start searching ride reports for Baja. It’s a motorcycle site but in my opinion it’s the absolute best resource for trip reports, locations, etc.
If I could spend the most time in any place in Baja it would be Santispac beach. We went there on the way down and back and during my next sabbatical we plan to do Baja again but with a travel trailer and spend weeks-months on the peninsula.
I would cross in Mexicali and camp the first night or two in cañon de guadalupe. It’s not cheap, but they’re awesome hot springs in the middle of the mountains. I recall it being like 30-$40/night. Do you have 4wd on your truck? Because there’s a bit of a stream with some clearance to cross. If I can do it on a 600lb bike with passenger you should be fine. There may be a different route in, not sure.
In Guerrero Negro there’s some whale watching. Unsure if it’s still going on in May. That was one of the most majestic moments of my life. They come down and breed in the spring.
We never felt unsafe and the friendliness of everyone was truly amazing. Blows away 99% of the US I’ve been to. My main safety advice would be get past the border the first night (cañon de Guadalupe is a great first night far enough away) and then the standard security measures. Lock your car, don’t leave valuables in site, etc. we never had a single issue.
A few rescources for a start..
http://www.bigdogadventures.com/1Baja2013.htmhttp://www.bigdogadventures.com/Baja2016.htmhttps://advrider.com/f/threads/we-need-help-picking-a-route-through-baja-with-a-gsa1200.1173656/https://www.cycleworld.com/2015/09/16/baja-mexico-adventure-motorcycle-road-trip-with-cycle-world-photographer-jeff-allen?image=10https://rawhyde-offroad.com/tours/north-america/big-bikes-in-bajahttps://advrider.com/f/threads/baja-the-long-way.864491/page-10