While RPGs are technically possible, anything beyond having some stats is going to require a lot of effort, as you'll have to write up the battle mechanics and all of that yourself. The scripting language with chooseyourstory is called CYS Script and you can read about it in these two places. Find good-looking articles and have at it.
Honestly, if CYS Script is too much to handle for a text-based RPG, a graphical one in RPG Maker isn't going to be any easier. Good luck either way. Since you mentioned that, I also want to point out this site just won't work for RPGs with graphics, since it's not built for it. That'd all be HTML/JS if you forced it to.