Do a quick search on youtube for some guides... just look up car upholstery and there is loads!
The head lining is easy to do, material + scissors + spray glue and your away but just make sure you try and get the creases out as you go along (depends on material)!
Sun visors are harder but there is a video on them too and requires a bit of sewing as unlike the head lining it's double sided.
Then the plastics is just some sort of interior polish/dye product to make it look nice (but generally they stay nice and black even after many years as they are more hidden from the sun).
Let me know how it goes

Lewi