Bought my first car last week

I decided it didn't need to be perfect after all I've only just passed my test so no point buying a brand new ford fiesta (learnt to drive in one and love it)
I don't have much knowldge about cars...at all.

SO what do I do about these problems and is it worth correcting them?

Bought a 1996 Fiesta LX 5 door for £300, in good condition, clean, engine runs fine no problems changing gear, although it doesn't always " click" into reverse.

one of the back doors doesn't open, not sure if its the actual handle, but it would be nice to have both doors opening.

steering is heavy as doesn't have power steering, i can manage it but is there anything i can do to make it better (sound like such a n00b!). I think the steering isn't properly aligned so I'll take it to a garage.

one of the wing mirrors doesn't move, think its the bit inside thats fallen off

Its got awful pink stickers over the car, what is the best way to take them off without damaging the paintwork.

its white, and I'd like it to be blue or black. changing the colour expensive? do I bother?

also the passenger seat doesn't move, the thing (!!) on the side just doesn't do anything, can't get it to slide backwards and forwards which if im in the passenger seat is a difficulty as im longlegged!

i think if just these little niggles were sorted it would be a perfect car for me. is it worth sorting? it really does run very well, the engine was well looked after and i could see myself driving it for aslong as it lasts