Im in Bangkok right now and flying to samui stay for 2 weeks and back to bangkok. Theres no onward tickets required right when i get back to bangkok or fly out from bangkok??

I meant fly out from bangkok to samui

Why would there, you aren't leaving Thailand. As a matter of fact, I don't think I've ever been asked for forward tickets, when traveling in the region.

Just asking, to make sure. Cause im not from here.

Flying anywhere within Thailand, you will only be required to show your passport when you buy your ticket and before you board your flight.

When you land, you get off the plane, retrieve your bags and exit the airport. No immigration.