Thanks for checking out. I found a way to make easier version of this code and I am working on a improved version (especially on wall jumps) I'll let you know when I upload it.
For coyote time, people generally uses a variable to jump control and changes it after a time (like 0.1 seconds) you can use timer nodes or you can use something like:
jump_variable=true
yield(get_tree().create_timer(0.1),"timeout")
jump_variable=false
I am still not sure how to make wall jumps better but right now I am working with timers (kinda like to early_jump codes in this version) to make wall jumps feel smoother
Let me know if there are more things that I can add in next version that you think will make controls better.