I bought Minecraft for PC but can't even play it, why?

The money has already been withdrawn, but I can't play the game.

I've already received an email with the order number and all the trimmings, but I just can't register. I keep entering my email address and password, but it just isn't accepted.

Contact microsoft support

You will probably have to download Java, hence minacraft was programmed with it

Does it cost money and where can you do it?

Enter java at google.

No Java does not cost any money and google just enter Java

Look at a tutorial on youtube otherwise there's a lot

The easiest thing would be to clarify the whole thing verbally, for example by phone, because I can't really imagine the whole thing here in writing.

It could probably be due to many different things.

Possible reasons are described here:

https://help.minecraft.net/hc/en-us/articles/360029643892-Can-only-play-Minecraft-demo-Java-Edition

Thanks