If I go the pub between £10-15 on around 4-6 beers. If a bar between £15-20 on around 4 or 5 cocktails (depending on deals such as buy one get one free or half price).
Rarely go clubbing any more because I just don't enjoy it, but when I went in first year I would spend very little money as focused on pre-drinks. Would very rarely and begrudgingly go to clubs where you had to pay entry. And when there not usually buy more than 1 drink unless going to some £1 shot places like the tequila place near me. So clubbing about £10 including taxi.
Cinema completely depends on your area, the time of day you go, the type of cinema screen you'll be using, cinema brand and how new the film is. Some places a ticket will cost you £5 here the Odeon can be £20+.
Never go to KFC but you can get meals for about £5. Prefer a pub meal myself in the region of £7-10.
In general how much weekends will cost you will vary a lot per area, for example nights out are very cheap in Liverpool. But in London will cost you 3x more + for the same amount of drinks and club entries.
It also varies per what your hobbies are. Also have to factor in transport costs such as buses and taxis, which will again vary per area and distance.