I need some help.

I have been trying to teach myself the fine art of fly fishing for twenty plus years. I usually get frustrated and give up for a while.
When I am casting the line will start whipping and making a popping / snapping sound. Thus breaking off and loosing flies.
Next about one in four cast will lie down on the water smoothly, rest of the time it will bunch up on the water.
I haven’t tied any knot in the line while casting, yet!
My rod is an 8’, 5/6 wt., with 6wt. Taper line. Do you think WWF in 6 wt. would help?

Thanks for your help.