Xenopolitan assumes you will play with 2 or more players (1 GM plus 1 or more players). Sessions might last an hour or more.
If you are new to role-playing, the Xenopolitan book has a very thorough example of play in the last chapter. It basically shows what an entire session of the game might look like with 1 GM and 3 players. This will probably answer some questions about how TTRPGs in general might work.