Depending on the rules you're using (D&D, Pathfinder, Savage Worlds, etc), you'll select a character sheet for all characters (and monsters) in the game. It's already made, you don't need Java or any programming. Then you go to the Journal and Add Character and then fill it out. There are more details here: <a href="https://wiki.roll20.net/Character_Sheets" rel="nofollow">https://wiki.roll20.net/Character_Sheets</a>