It's possible to bring your followers with you by doing an account redirect. On your old server and/or account, go to Preferences->Profile and then scroll down until you see move to a new account and click on the link. Then on your new server and/or account go to Preferences->Profile and scroll down until you see move from a different account and click on that link. Your follower will be alerted as to your new account. Right now you aren't able to bring your posts over with you. Unfortunately it is not possible to even export your posts yet with Mastodon. A part of me is regretting not going with Akkoma or Calckey when I decided to redo my Mastodon instance because I believe those twitter-like alternatives give you the ability to export/import all of your data.