If you want to restrict or screen who can follow your account on Mastodon, you can switch your account to "follow requests" mode. When this is activated you will be able to accept or reject followers before their follows become active, so you can accept the ones you want and reject the ones you don't want. More info at:
➡️ https://fedi.tips/restricting-who-can-follow-you-in-mastodon
This guide also answers lots of questions about follow requests. Let me know if your question is missing from the guide.
