How do I configure hammer for gmod

I have previously used hammer sdk with gmod but since have forgotten how to get it to work

I don’t own css or half life
Is there any easy way to go about this, many or most tutorials are outdated on youtube

*I have reinstalled all my gmod and hammer sdk related stuff because I was tampering with the settings and most likely made it worse.

Gmod has its own Hammer in the Garrysmod/Bin folder already set up

It used to be so much more difficult :stuck_out_tongue: