What kind of RPG are you wanting to make? Something that is text based or do you want graphics? If you want it to be graphical (even 2D only) I wouldn't use C, especially if you want it to be cross platform. I would take a look at an off the shelf video game engine and IDE instead and write in something a little higher level. But it really depends what type of RPG you want to make and how complex it is going to be.
However I will warn you that games are hard and don't overreach on your first coding project. It doesn't need to compete with the Elder Scrolls games.