1) relax... easier said than done but it comes with time. things will work better and you'll tire slower when you do

2) accept that you will 'suck' you're new at this and you won't get better sparring somebody who is not a level above you

3) if you do get hit... it's because you put yourself in a position to be hit... this is a GOOD thing... you need to be willing to try things so that you can learn what you can and can't do in the ring.

4) focus on defence... I don't mean back pedalling with a guard up... going back to what I said in 3) if you don't put yourself in a realistic position you won't learn... but try and use as many slips, parrys and rolls as you can... again you will likely mess them up... but everytime you do mess it up you are a step closer to figuring out the: angle, timing, range and suitability for everything you want to do

Stick with it, enjoy it and try things! You're there to learn, not look great! Enjoy!