Here is my input. I was a climber for many years. Although many knots can be tied, only a few are generally useful on a regular basis.

learn how to tie a "water knot" in webbing. that is very important. it may go by other names, but it is the basic knot for joining two ends of flat webbing together.

for ropes, learn a "Figure-8" which is used for making a loop, a "clove hitch" which is very useful for attaching a rope to an anchor, and a "Double Fishermans knot" which is very important for joining two ropes together. I never used the bowline or the square knot, but some people like the bowline.

good luck,
Pete2