How can I easily move repos from Github to a European alternative?

Codeberg or a selfhosted Forgejo would be my recommendation.

Moving repos is easy, but expect some sweat while moving actions and integrations. Also do backups.

You can always push your local copy to any other origin and Codeberg offers a service to clone github repositories. It is just a couple of clicks.

Codeberg is good and will be even better if we donate regularly.

Kinda difficult to do it in a way that isn't easy tbh!

Just locally rename your old origin to old-github or something, add your new origin (codeberg is a good shout) and then push. Maybe put a notice & link on your old repo's readme and then archive the repo on GitHub

Job done in less than 5 mins per repo

I switched from github to forgejo and that was really easy, they have an migrate button.

Yes, Cideberg will do. And probaably mirroring code into Codeberg is good enough

If you used Github as a simple remote repository and nothing around (CI, issues, ...), you can also setup a simple bare git repository on a server to use a your remote and a backup. There is nothing special to do once you can log with SSH into the server.

I very recently did that for my personal projects.