It makes my blood boil that this is still an issue in 2022, as it was when I was a similar age in the 90's. Cat-calling, staring (you know what I mean), tongue-clicking, following...all of these things happen regularly to my teen DD when she is out in town (large city). By far it's mostly much older men or in their twenties upwards.
The first time it happened she was withdrawing cash from a machine (aged 12) and I was waiting for her a few metres away. Cash machine was next to a bar and a middle-aged man sitting there started making comments to her. I was horrified and marched over and said 'She's 12! What's wrong with you?' He seemed completely unbothered.
So...best advice for teen girls to handle this kind of hassle and misogynistic bullying, please? I've told her to give them a cold stare; walk away; look utterly bored etc...as well of course as going into a shop if she feels threatened etc.
What else? How can this be tackled? I almost wish it was legal for women to simply spray these sorts of men in the face with some foul liquid, in a similar vein to hosing down randy dogs 
. Maybe that would sort the problem.