1. Focus largely on what you can control
Focus largely on what you can control during your conversation. That list includes your preparation and rehearsal (vital) and overall attitude (even more vital). Try not to obsess about what the coach thinks of you or whether they approve of you or not. You can influence those things for sure, but you can never control them (coaches might only like players of a certain build, or background, or state). Why not direct your focus and energies towards the things that are in your power?
2. Rigid desire = bad, Flexible preference = good
Remember to keep things in perspective when you talk to coaches. For example, your conversation is important, but not all important. The reality is that win, lose or draw, you have a long life ahead of you with many more swings at the bat. To this end, stay clear of negative self-talk like “I must do well,” or “I have to impress the coach.” These kinds of rigid desires are breeding grounds for the worst types of nerves or jitters. 
Instead, make sure your desires are flexible preferences. For example, try this thinking on for size:
“I really want to present myself well in front of the coach. In fact, I’m going to work hard at role play with my parents, dedicating an hour a day leading up to my meeting with the coach. I think this will leave me mentally prepared and confident for the meeting. It’s what I can control. Ultimately, I hope the meeting goes well. But if it doesn’t, I’ll quickly regroup and try again, allowing the key learnings from the meeting to make me better on my next try.”
What a difference between this and “I must do well!” The self-talk above works great because of its flexibility. It doesn’t naively assume that things will go well (they may not!). And it prepares a contingency if things don’t go well that bounces you right back on your feet stronger than ever. What’s not to like?
3. Slay fear with “What’s the worst that can happen”
To really slay nerves with the coach, try asking yourself the question, “What’s the worst that can happen?” and conclude that the worst that can happen is not all that bad. This is an ancient mind hack that has been around for a few thousand years – at least since the ancient Greeks and Romans. The reason that it works so well is that the mind very naturally concludes that the worst that can happen is “horrible or terrible” and hence breeds fear, which multiplies into more fear and so on. Asking yourself this question nips that process right in the bud and allows you to live a bolder and fear-free life. Now that’s Hub-approved!
4. Accept it
Here’s an old adage that we love here at The Hub: “You can’t stop the butterflies, but you can get them flying in the right direction.” Keep in mind that in many instances you might have a few butterflies in front of the coach. That’s fine! The trick is just to Accept it. This attitude is reflected famously in the Serenity Prayer. 
There you have it. A few good tricks to managing your nerves in front of coaches. Useful on your college visits for sure. And the best news? Useful in life!