Board Game Arena

I created a new tutorial project named reversidean. When I open it, I see this:
This game doesn't have a valid BGG_ID. Please fill in this information in the gameinfos file and reload the game informations.

I don't know how to find the gameinfos file.

I clicked "Check Project" which generated these and other warnings:
README.md Error: Error loading file: File not found
gameinfos Warning: BGG info check skipped: BGG XML API is blocked (requires auth token since Oct 2025)

When the project was generated, there were messages about unauthorized access that I can no longer see.

When I signed up as a developer, I chose the same ID that I use for playing: nightrider (all lower case). I received a welcome letter that began "Dear nightrider0". Is that normal?

I tried to follow the "Great, I'm in! ... How should I start?" steps, but I must have done something wrong. Can someone tell me what?

Ignore the bgg warning if you're not developing a real game

You can continue the tutorial wiki, also ignore the Project check. And you have 10 users from 0 to 9 for testing, that's perfectly normal.

Many thanks for that information.

Now the First Steps say that...
'Your projects will be listed in the "home" folder. If you have already created a new game project, you should see a folder with the project name be in your "home" folder.'
... but I don't know where to look for the "home" folder (or did I miss an earlier First Step) ?

As a developer, you have a "home" folder on the BGA servers where you save all your projects (each project will be a folder containing code, images, etc.). To access it you will need a SFTP software, the getting started wiki has a couple suggestions but ultimately you can choose one to fit your operating system and preferences. Install a SFTP software, and then with that software you can establish a connection to the BGA server using the SFTP credentials in that welcome email you received. Most people have a local copy of their project files on their machine to work with and sync them to the server using the SFTP software to run them.