I would like to create a website for a Minecraft project and am not sure now whether I need an imprint.
In general, always create an imprint. There are generators for this:
https://www.impressum-generator.de/impressum-generator/
You are offering a service that can be made available to any third party. You are therefore subject to the imprint. You will probably also have to keep a privacy policy and, if necessary, terms of use in hand.
Yes, you probably even need the complete range from imprint to GDPR-compliant documents.