What Should I Play?

Have you tried Fabula Ultima? It's based on JRPGs, and it's built on having multiple classes. In fact, you start with levels in 2-3 classes! The combat is also quite easy. It all feels very video game-y but it's quite easy to understand, and the inventory system is also lovely. (Instead of having items, you have inventory points, and when you need a potion or something, you just detract the needed amount of inventory points. Really good for the part of me that always hoards consumables because "I might need it more later.")

There's a quickstart available that runs you through it very well! It even has numbers on the pregens' character sheets that are like. Don't look at this part yet; that'll become relevant in part 3. I suppose that's also based on good tutorial design in video games; things are explained in gameplay instead of rule-dumped at the start.