You can go to the database services on Railway, clicking on them will reveal a tab that shows your database's deployment history. From there you can then remove the running deployments.

Note, it will still incur usage due to the data stored in the volume. If you want to avoid that cost as well then you'd need to download a backup of the database to your machine and then delete the volume.

Thanks, and for the nest and next containers?

Same thing, you just remove the running deployments and you should be good to go, with the exception of volumes as explained above