Driver aids and penalties are set by the host room. I generally leave them on when racing by myself, to work on spotting lines on tracks and stuff. To join- you can either get the room id# (16 digit number broken up 4x4) or find a friend online that's in the league, and join whatever room they're in, which would theoretically be the league room. That's the easy way. When you go to "Community" in GT mode, it will list all the friends you have that have the game, whether or not they're online. Click on that friend if they're online, and it will bring you to a little coffee cup, that will say lounge, and in the upper right hand corner of that coffee cup, there's a little (I wanna say gold, i'm doing this all from memory) icon that you can click on to join the room. From there, it's pretty self explanatory.