You are wise to be cautious about Ivy league admissions – many of us parents grew up at a time when it wasn’t that hard to get into the Ivies or other top 20 schools so came into this process the first time around thinking that, a smart kid with good scores and activities stands a chance for acceptance. Scrolling through the trail of heartbreak and disbelief on some of the other boards here will show that it is a real disservice to tell kids nowadays that, “they are smart, good scores, sure you’ll get in wherever you want.”
My own experience, with two kids through this, is figure out the type of school you are looking for, and then build a list with safeties and matches first, then add on the reaches, since those are pretty easy to identify. Have the finances talk with your family, now. That is another area where things have changed, and most of us parents do not really appreciate that the total cost for full pay families is more than $250,000 (most schools average around $60,000 year now, and will increase over the next few years). Get your parents to run the Net Price Calculators on some schools’ websites to see if you qualify for financial aid, at all. If you don’t, but your family isn’t in a position to write $60,000 checks for four years, then you are looking at finding schools which will give you merit awards. That means, focusing on schools where your record puts you in the top of the class. Some schools don’t give merit awards at all, including the Ivy League and NESCAC (Amherst, Bowdoin etc).
Sports recruiting does affect this process, mostly in terms of timing. Figuring out where sports fits in your priorities, as well as the type of school you want, is a priority. If you want a big university, I am guessing those will largely be D1 and will have wrapped up recruiting for the Class of '17 by now, or will soon, though I admit, I have no familiarity with tennis recruiting specifically. D3s tend to pick up now, and get finalized by Sept-Oct, with ED decisions being made for the Nov 1/15 deadlines. So my advice would be, focus on how much tennis matters to you in college – is it leverage to get you into a certain type of school? Or is it so essential to your experience as a college student that you will go where you can play?
Some smaller schools are D1, including Davidson, Lafayette, Bucknell, Lehigh, Colgate. Some bigger schools are D3, such as MIT, University of Chicago, Brandeis, Emory.
Good luck, and take the opportunity to talk with your family about college finances and about how the application process has changed since their day.