What people do in that case is look at pictures of people with various hairstyles online, trying to find one where they feel like “this looks good, I want to try that one”

I don’t know what problems OP is facing, but in my case, this is basically what the hairdresser recommended that I do and also what I tried doing. Except it didn’t help because nothing was appealing to me (I’m rather change adverse). I really needed to maintain a particular style for a while to get used to it before I could decide if I liked it or not. After a while, I couldn’t tell if I disliked it because it was grown out too much or if I just didn’t like that cut, or if it was some other reason.