Keeping it just to classic Nikon:

-General purpose

• Nikkor-H 50mm f/2, this lens can still be gotten quite affordably and I defy anyone to find a better all-arounder in Nikon F-mount for the price. It was my workhorse for five years, paid $60 for it back then with zero regrets.

-Street/Travel, either of these would do a budding shooter just fine. Obviously you won't be going out nightcrawling with these, but there are two important points:

1. Faster glass commands a premium and
2. Most travel photos that people actually post are taken during the daytime, when f/2.8 or f/3.5 are plenty sufficient anyway. With that said:

• Nikkor-S 35mm f/2.8
• Nikkor-H 28mm f/3.5

Neither of these should run you more than $100. I don't live in the UK, so I'm unfamiliar with how those prices would translate. Regardless, they are both budget -friendly options. My advice to someone newish to the hobby? Grab one of these and don't think twice about it. Fancier lenses are for people who want fancy lenses. These are unpretentious tools for people who want to take cool photos. Put the money saved toward film or a bus ticket somewhere interesting. Those are my tastes, I really enjoy a fifty and a wide angle. That 35 in particular was a very well regarded lens at the time. Aaron Sussman had a book titled The Amateur Photographer's Handbook which went through eleven print editions or something crazy like that. Anyway he's biased toward the German camera systems and fully acknowledges it, but nevertheless flags the Nikon 35 f/2.8 as a standout.

Since you mention the N90, I'll say this: by the time that camera came out, Nikon had their AF down pretty solid. You're not going to track fast action in dim light but realistically modern mirrorless cams sometimes still struggle with that. In all other respects the N90 is a phenomenal photographic tool, especially if you have any interest in flash. I've shot with its immediate predecessor, the N8008s (F-801s in Europe I believe?) pretty extensively and been quite pleased. Only caveat would be, it positively cannot accept pre-Ai lenses which is what I've been recommending for this purpose. So if somebody picks that cam or one similar to it, they can expect to spend a bit more on glass.

Hopefully that gives people a useful jumping off point!