Hello, Ricardo and welcome to the rFR League!
First of all, make sure to check and read all the info and links inside the link below - and complete all the necessary steps to be able to join our league (especiallt the topics about the rules and the anti-cheater):
http://www.rfactor-racers.com/t1509-joining-the-rfactor-racers-league-read-this-first#29739Secondly...
Every new driver in the league (who hasn't took part in the team selection process during the pre-season) will begin as a Reserve Driver - driving the Reserve Car.
And only after a few races (showing commitment to the league) and without causing problems (crashes or disrespect to the rules), you will be given the chance to pick one of the free seats - to pick a car.
So, for now, you will have to drive the Reserve Car.
ALSO...
All the new drivers to the league must start their first race in the league from the pits.
More info about this, can be found here:
http://www.rfactor-racers.com/t2256-how-to-start-from-the-pits#36647Other than that... You just need to download the mod, the tracks and practice on the server to be ready for each race (never show up and race, without practice).
If you get everything set properly until sunday, you'll be allowed to race.
And if not, you can try again for the following race - but you will only be allowed to race when everything mentioned above (all the necessary/mandatory steps) is set properly.
See you on track (if everything's ok)!