Wool is delicate material, but when you take properly care of it, it will last for years. Knits may fuzz over time, especially when the knit is new. Fuzz can be easily removed without damaging the knit with wool comb or electronically fuzz cutter very gently.
You can also sew or patch your knitwears to make them last longer.
Wool washing instructions
Air your knit often and fold it between uses. Do not wash often and when you wash use cool water.
When washing by hand, use wool detergent with cool water. Wash by pressing the knit gently. Do not soak or rub knitwear while washing it.
I don't recommend machine wash, but if washing instructions don't deny it and you want to use it, use a laundry bag and wool program 30 degrees. Do not spinning, bleaching or tumble dry.
After wash, wrap the wet knit in a dry towel and press to remove excess water. Dry on a flat and let it dry. You can shape your knitwear while it's wet.