After signing up in the browser, you will need to use the command line to give your newly created account admin privileges. Assuming your username is `alice`:
Prior to Mastodon 4.0, roles were hardcoded to be one of `user`, `moderator`, or `admin`. Since Mastodon 4.0, there is a customizable role system, with default roles created for `Moderator`, `Admin`, and `Owner`. Names of custom roles are case-sensitive.
After logging in, navigate to the **Site settings** page (under **Preferences** -> **Administration**). While there are no technical requirements for filling in this information, it is considered crucial for operating a server for humans.
Mastodon generates some temporary files that are worth cleaning up after a certain amount of time (e.g. to save money on hosting). In general, you want to set up `cron` jobs (or another mechanism) to run these periodic cleanup tasks.
Typically you want to run [`tootctl media remove`](https://docs.joinmastodon.org/admin/tootctl/#media) and [`tootctl preview_cards remove`](https://docs.joinmastodon.org/admin/tootctl/#preview_cards) periodically. These will clean up remote media (e.g. images, videos, audio) and preview cards (e.g. preview images for links) after a certain number of days. (Check the docs for those commands if you want to tweak how old something has to be before it's cleaned up.)
First, run `crontab -e` to edit the cronfile for the `mastodon` user. (If you get a prompt asking which editor to use, choose your favorite editor.)
Next, add something like the following to the bottom of the file:
@weekly RAILS_ENV=production /home/mastodon/live/bin/tootctl media remove