You can transfer your Mastodon account to a different server if you would like. The process allows you to keep your follows, followers, bookmarks, lists, mutes, blocks and domain blocks. Your old posts will remain on the old server, but they will redirect people to your new account.
There's a complete step-by-step beginner's guide for how to transfer your account at:
https://fedi.tips/transferring-your-mastodon-account-to-another-server
It might seem a bit long, but it combines several processes into one guide.