Heads up! This is a guide for admins. If you're not an admin yet, ask your Beacon admin to promote you so you can start managing fields.
The sidebar in your Beacon database is, quite simply, a list of record types that you can easily access.
You can re-order the items in the sidebar, hide ones you don't need, or add to the sidebar any new record types you've created.
Head to Settings > Sidebar to make any changes.