I did the whole "knot" thing when I got serious about mountain climbing. A long time ago, but I still remember my knots.

I only use about 3-4 of them. It's enough to do everything - pretty much.

Loop In A Rope - Climbers don't use a normal knot, but instead the Figure-8 knot. Easier to untie, after the rope has been stressed.

Webbing - standard knot is the Water Knot. Everyone who works with webbing probably knows this one.

Joining 2 ropes - my most important knot. The Double Fishermans knot. My life depended on this knot so many times, I have lost count. It never failed me.

Clipping to a Carabiner - yes you can use the clove hitch, and it works well.

Have fun.
It's "knot necessary" to know a lot of knots. Just a few that do the job.

Pte