How to tell your position

At a six-handed table your position is not a fixed chair. It is your seat relative to the button, and the button moves every hand.

Find the D button. If it sits in front of you, you are the button.
The blinds are to the left of the button. Small blind first, then big blind. Online, those chips are already posted.
The first to act before the flop is UTG. In 6-max, hijack and cutoff sit between UTG and the button.

Open or fold6-max · 100 bb

BTN · Button

You act fourth before the flop, and last on the flop, turn and river.

How to tell. The D chip is in front of you.

This is the best seat. You see what the others do and close the action on later streets. The button open is the widest.