What to do if the buyer does not pay for the product sold?

I sold a notebook on the http://www.digitec.ch online platform. The notebook arrived according to the post. I emailed the buyer whether he had received the product. And he wrote me that he has it. Now he has still not paid for it and he has not responded to another email from me. What can I do now?

If I have to take legal action, will I have to pay for it myself? I don't have the money.

Unfortunately you have no choice but to go to the police first, if he has to pay a fine for it.

Dunning procedure. https://www.online-mahnantrag.de/

In the event of a contradiction, take legal action.

Since when have the police been dealing with civil law matters?

Because you can display something like that

This is initially only about an unpaid bill, the police have nothing to do with it. The way leads through a dunning notice.

Achsu soryy for my wrong

Because you can display something like that

Even,. If there was a fraud here, the civil law story, i.e. The money for the seller, does not exist.