Oh oops A0;
You could make some sort of RPG
I definitely do not recommend starting off your first game programming project with an RPG.
RPGs are just too involved, even text ones. You need to come up with a story, characters, enemies, menus & actions, world maps etc. You then need to come up with reasonable algorithms for doing battles and other stuff (think about all the RPGs you've played. How much do you actually know how they calculate damages etc. in battle?). I'd save RPGs for
much later. In fact, it might be best to create RPGs not using an actual programming language but things like RPGMakers that already provides the backbone of an RPG engine so that you can focus more on the game design aspects of things, which for an RPG is like 90% of the game if you think about it.
Are you going to go into a different Screen mode and use graphics? Or stay mostly text based?
For QBASIC, I'd suggest forget about doing graphics. The support for it is just too primitive, it's not worth the trouble. And in any case, if you're going to start off
small, text is the way to go.
How much experience do you have with QBASIC? If not a lot, maybe you should start on some smaller games first before trying a big project.
It's also good to keep in mind that in creating the game, there's game design and then there's game programming. Since changing things in the program is generally harder and more troublesome, it's best to work out the game design to a point where it is mostly finalized, then program the game off of the design.
Sometimes you might design games that you never end up programming to completion either because it is too much trouble or because you don't have the know-how, but at least you have a game concept you can go back to in the future or share with others.