If you want to find interesting accounts to follow, there's a guide here: https://fedi.tips/how-do-i-find-accounts-to-follow-on-mastodon-and-the-fediverse-how-do-i-find-my-friends/
If you want to follow people you already know, the surest way to do this is to swap account addresses. There's more about this here: https://fedi.tips/whats-my-accounts-address-how-do-i-follow-other-peoples-addresses-how-can-people-follow-my-address/