As long as you follow the full procedure to migrate, you can keep all your follows and followers. (Instructions are here: https://fedi.tips/how-to-use-mastodon-and-the-fediverse-basic-tips/#TransferringYourMastodonAccountToAnotherServer)
The transfer procedure is slightly complicated though, so if you're just getting started and don't have any followers you might want to just sign up elsewhere and delete the old account.