One thing my very good assistant does so well is he fills dead time. If he sees a group dragging along, or I'm hung up with something, he immediately engages some guys and gets them busy... usually something as simple as a bunt drill, fungos on the side, or ground balls on the side... I look up and bam, he's got 'em going on something rather than waiting on me. then if i need them back on the regularly scheduled stuff, i holler and away we go. I appreciate him seeing the need and getting the kids active... discuss things with your head coach and find out his expectations for you. I give my guys a chart at the beginning of the year that has things on it like who's in charge of calling in jv scores, filing game notes and scouting reports, inventory of gear, etc...
just talk with him a lot.
2) When the day comes, and it will come, that a parent approaches you about more playing time do not give them an audience. They will say, "what can jonny do to get more playing time?" and you (in my opinion) should say, "we've got lot's of kids trying hard out there so you will have to talk to coach about that one."
3) have fun and put a smile on your face. Kids would rather be around you if your happy to be there. Have fun and best wishes... the game needs you.