Hi, Mastodon. 
@hollyoreilly hello. Trying to find friends from the twitt show. Followed each other there.
Welcome. I’m trying to figure this all out too.
@Jarhead80 @hollyoreilly Did you use one of the import tools to bring your followers over?
@jcheroske @Jarhead80 Oooh, there are import tools?

@hollyoreilly @Jarhead80 Yeah. There are several guides out there. The basic jist is that you'll go to an importer website. Then you'll authorize your Twitter account (login essentially) so the tool can see all your followers, follows, blocks, lists, etc. Then you'll pick what accounts you want to try and import (e.g. your follows). The tool will search those Twitter accts looking for Mastodon handles in the profiles and will write a CSV file that you then download. Then you go into the Mastodon web interface and find the import section within your profile settings. You'll upload that CSV and bingo, you've got a bunch of new follows. I had about 1100 follows on the other site, and over 100 are here, so pretty good I think. You can rerun the tool every few days to grab any people that have signed up in the meantime. Tell people to come over here, and tell them to put their handle in their Twitter profile.

Here's a link to a guide: https://www.tomshardware.com/how-to/move-from-twitter-to-mastodon

How to Move From Twitter to Mastodon

Free the bird

Tom's Hardware