Condolences on your loss and congratulations on your desire to keep on RVing. YES, there ARE schools AND independent driver instructors for RVers. You don't say where you are so, I'd recommend you start with a Google search for "RV Driver Training"
Some instructors will come to you and, teach you using YOUR RV. I have seen training offered at major RV rallies (sometimes before and / or after a rally). I'd also recommend you find and attend an RV Boot Camp. Mistakes made with RVs are often costly and, sometimes dangerous. Now that you're on your own, it would be wise to spend a couple of days to update / expand your RV knowledge. The Escapees RV Club run an excellent RV Boot Camp (there are other providers too). It seems to me that your instincts are good so, listen to your inner voice and, keep asking questions both here and, on other forums. Remember that checklists are an RVer's friend. A good checklist will help ensure that you cover all the bases, especially now that you're doing it all solo.