You don't really need to go with others for safety or security. We have been roaming around Mexico during winter months for over 10 years and never had a problem (first camping trip through Mexico in 1971 and many other trips since then - regulars for at least 10 years now). There are a number of websites where you can learn where you can park an RV - RV parks - campgrounds - we sometimes stay in Pemex stations though rarely. You need to figure out your route and then ask specific questions here to plan where you will stay and what you will do. Personal opinion - Belize - Honduras - El Salvador - Guatemala - all have far more crime and are far more dangerous than Mexico - those are places I would want to ask for help.
This website has road logs and a whole lot more for learning about travel in Mexico . . . http://www.ontheroadin.com/the-app-store/ . . . we bought their logs years ago and printed them out in a loose leaf notebook where we continue to write our own notes and updates.
These folks . . . http://www.rollinghomes.com/ . . . wrote great books about camping in Mexico but they haven't written a new one for several years now. But the book is still useful and the website has updates to the books sent in by those who travel Mexico.
Maybe other people will post more tips. Tell us more about your plans and where you want to go and what you want to do. We have never caravaned with anyone and know many others who also roam around Mexico on their own - we like the freedom of moving on our own. We hope to be heading down after Thanksgiving (too hot before then) so we can't help you much on your scheduled travel dates.