I'am about to start an IT company.
Among other things I need Terms-and-Conditions and Privacy-Policy documents. As far as I know I can get such by:
I know what the content should be but I don't want to copy-paste from other websites, instead I would like to use the same content as theirs, but in order this to be legal first I have to find who sold them the documents and to buy these documents from the seller.
So, how can I find this template, or how can I buy it.
Assuming you actually want to be legally protected, and considering you're not a lawyer, you shouldn't be writing your legal copy, and you certainly shouldn't be copy pasting it from templates.
If you go down this path, the time you will wish you hadn't, you'll already be in a whole world of pain, likely costing you far more than talking to your lawyer.
The answer above, and your own experience, make it clear that you should just hire an inexpensive lawyer to do this for you. You're walking into a minefield by doing it on your own.