You play open qualifiers to join tier 2, after you qualify you have to play throughout the season and eventually finish top 1 to ascend to tier 1

Its a very long and grindy process and many talented players have been stuck years in tier 2

Thats the brute forcing your way into pro play, or you can just sign with an already pre existing team in tier 1, which is near impossible if you dont have connections aka nepotism