Every Avenue 510 account can be an Affiliate account. There is no separate signup flow. Create a free account at /signup, then open the Affiliate portal inside your account and accept the affiliate terms. Your invite code pool unlocks immediately.
The free plan gives you 7 days of full platform access (card required at signup, $0 charged). After 7 days you either upgrade to a paid plan or your platform access converts to portal-only. Either way your Affiliate portal stays live and your referral earnings continue regardless of your subscription status.
The Partner tier is application-only. See the Partner program article for the application process and the 40% commission + perks structure.