Hello,
First step is always to apply with registration fee. After you account is reviewed and approved you become a member on Tier 2 for 30 days.
Then if you would like a higher Tier you can add it to your T2. There are various ways t do it : delegation, upvotes, subscription.

All details you will find in this post.
You can also join our Discord and talk to the Mods if you have more questions. :)