Now, of course, if you make an RPG, it's yours, and you can handle it any way you want.But here are a few tips, and why.
-Explain. Explain the game on the OP; the setting, what your goal is, and who your character is. I thought I wouldn't have to say this, but apparently so. I mean, if you're just plunked down with a character sheet, the game could be about flying elephants or knights in castles, and you won't know. So explain, or the player will be confused. -Character Sheet. I cannot stress this one enough. You should have a character sheet, for keeping track of everything and also so the player can better see what is happening. But another tip about character sheets is not to make them too long or complicated, or it will be a wall of text, too complicated to play. -Update. Update the RPG often, or the players will get impatient and quit. Unless of course you're going on a vacation or something. And of course, the same thing goes the other way around. If you don't reply to an RPG you're on,for a long time, you probably impede gameplay, and you might be booted out of the game. So it goes both ways; update often.
Those are three of the most basic rules to creating an RPG. Hope I helped.