Basics of fighting?

For this thread I use fighting in the sense of full contact sparring or comps, not a self defence situation. I had been doing boxing for about 6 months and have been doing taekwondo for about a year. My basic punches and kicks are good, not spectacular but my rear leg roundhouse sure packs a punch and my basic technique of most strikes is proficent at least.

my problem is I have no idea what to do in sparring. The guy that teaches us is a really nice guy and one of my best friends but isnt that great, its just a univerity club run by students. I feel like im progressing slower than other people in the sparring because I dont know the basics of how to just fight.

I feel like I would really benifit from just going over the basics of how to fight. When I move in, I get countered, when I stay outside kicking range nothing happens. When I kick it rarely lands, when my opponent kicks It really throws me. Im quite confident using my hands in boxing, but as soon as kicking is introduced it just messes me up. I like to use my jab to establish range, and fight from the outside, but I find that that range in taekwondo is the perfect range for me to take lots of kicks. 

I think my biggest problem might be my lack of confidence with defense, because im always trying to make sure I can block a kick, I dont attack often enough. Im too hesitant