And do I only have one ssd slot?

Can I connect a Ryzen 7
5800x 3.8 ghz cpu connected?

A BS is never included, if you need a BS you can buy it cheaply.

No matter which MB you always have to buy one.

Hmmm, the mainboard itself has no storage medium or other components (CPU, RAM etc.), so it can't have win 11 on it. The mainboard has two m.2 memory slots, which you can buy separately. You can find an OEM Windows 11 version on the official website and you can buy a key cheaply on eBay. Regards

Is not installed. You have to buy Windows 11. Windows is stored on the hard disc.