Click on the race icon choose "challenges" select the second Race track with the "ranked" tag, try to do your best time to get on top 10 or top 100 best souzasim racing teams!!!..
How to team up with someone?!
Tell your friend to have the same team name (in the team name select menu) and you guys would be compete other teams this way. make your team reach in top 10 or even top 1!
if you don't want to be in a team. just name your team however you like and you would be an individual team.