congrats. i remember my first sparring session vividly, great fun then and it only gets better. just some things to keep in mind as you progress:

you will have good sessions and horrid sessions, learn from both varieties.

dont worry as much about how you do as how you learn, thats the most important part. ive learned more getting my ass beat so bad i didnt even want to go back to the gym than i have running the table against a bunch of people all day.

if you have means of video taping it, do so. it's a lot easier to see your flaws from the third person than the first person.