If at all reasonably possible, try to find a place where drugs can be tested to see what they really are (sadly a rare thing still, but it exists).
The next best thing to do is talk with people in the scene and find out what they consider a trustworthy source. Any single person trying to offer you pills is a potential scammer or worse, you need to verify from other sources whether they're legit.
There's probably a better than 50% chance you'll get something close enough to what you want regardless, because incentives are aligned with everyone having a good time. But just like everywhere else, bad actors will always exist.
The next best thing to do is talk with people in the scene and find out what they consider a trustworthy source. Any single person trying to offer you pills is a potential scammer or worse, you need to verify from other sources whether they're legit.
There's probably a better than 50% chance you'll get something close enough to what you want regardless, because incentives are aligned with everyone having a good time. But just like everywhere else, bad actors will always exist.