but there is si many red flags for selling around and i cannot figure out how to do it safe.
in first place, it is not good idea to use self-moderated or locked topics because i am newbie and i cannot protect myself from trolls and competition, in other hands you highly doubt to find escrow who will help about the security of that kind of sales.
so what should i do ?
Yes, there are so many red flags for selling around and for buying around, as well.

You have to understand that the bitcoin transactions are irreversible so the customers are at a disadvantage in here, unlike, for example, ebay. If you open a self-moderated topic you have protected yourself from trolls and competition but what protects the buyer?