I was in secondary school in the early 80's.
Then, I think a fair proportion of society was homophobic, and the advent of AIDS did absolutely nothing to help matters. The 'gay plague' (yes, it was really referred to as that). 'Queer bashing' was seemingly commonplace (physical assaults on gay men).
Back then, I didn't know a single other pupil who was gay or lesbian, or bi. I am sure some where, but it wasn't known. There would be geeky kids who might be referred to as a 'poof', but that would largely be based on their physicality, or manner.
Some under 16's had sex. A few more claimed to have, but I'm not sure many really did.
Pornography was typically limited to magazines stolen from someone's dad, or occasionally a 'blue movie' if someone had access to their parent's video player without their parents being around AND knew where their dad's video tape was (or it had been hired). This was relatively rare.
'Heavy petting' was as far as most of us got.
Drugs were really just smoking cannabis at parties and still relatively rare. Glue sniffing was a serious issue though. In the early 80's bags of glue would often be found in the street in alcoves or back alleys. I recall it being such a problem, that all sorts of regulations came in to limit the sales of glue and other substances.
I think I started going into pubs at about 14 (I looked older). Most pubs never batted an eye at kids 15 or 16 years old, and I'm sure they knew very well our ages.
I never once saw anybody carrying a knife. People didn't bring weapons into schools. Fights would be fist fights and short lived.
There were no gangs, although there would often be small cliques of friends. There would be 'New Romantic' types or 'Heavy Rockers'. No punks were left. There were a few unto (then) underground stuff like Joy Division, or Echo and the Bunnymen etc, but it was mostly New Romantic or Heavy Rock.
'Fuck' was still a very naughty word
'Cunt' was utterly taboo
'Twat' was getting popular
Uniforms were strictly adhered to, but kids always pushed the boundaries. Thin ties were common (we'd tie a school tie the wrong way round, so the thin end shows). Super fat knots where also a thing.
White socks (for boys!) were a thing AND 'Kickers' footwear was amazingly popular. If you didn't have a pair of Kickers (with lots of 'tags' on them, you were nothing).
'Backing books' (wrapping the covers in a poster, or some form of art) took off. It was the teachers who pushed it, trying to make the writing books last longer, but the kids got creative in using posters of pop groups or football teams)
Some teachers wouldn't think twice about calling someone an 'idiot'.
School trips were quite rare and I'm not sure if there was ever any foreign trip (might have been, but damn rare!)
End of year discos at a local disco / nightclub were common, and I can recall one male PE teacher being surrounded by girls in an alcove.
Bullying happened, and I think most people experienced it at some point. A relative view probably bore the lion's share of it, but as others have said, after school, there'd be some respite.
I never witnessed terrifying bullying (not that I want to grade levels of it). It was usually taunting / name calling / degrading nickname.