By Linda Marx
Updated November 07, 2003 01:00 PM

U.S. Open tennis champ Andy Roddick is live from New York this weekend as host of Saturday Night Live, but the hunky No. 1-ranked tennis star still made time this week to stop through his hometown of Boca Raton, Fla., and walk the runway at the Arnold Brant fashion show – a fund-raiser for his Andy Roddick Foundation benefiting neglected and abused children. Roddick, 21, talked to PEOPLE about hosting SNL, starring in a new reality show and finding time to see his girlfriend, actress Mandy Moore (who joined him for the charity event).

So, are you getting nervous about SNL?
I am more nervous about hosting Saturday Night Live than I was going into the U.S. Open! I have been rehearsing all week. I’m going back to New York right after the fashion show to continue rehearsing.

Are you going to be funny?
Yes, I hope to be! I hope I’m funny. But it’s a secret till Saturday.

With all of your obligations, how do you make time for your relationship with Mandy?
Well, our relationship is not ideal because of the time restraints on both sides. But we work hard at making it work. We relate to each other, and we make sacrifices to see each other.

How does it feel to be ranked No. 1 in tennis at the age of 21?
It is surreal. I really wanted tennis to give me a college scholarship. But I feel no different now than I did when I started. It is nice to be where I am, but I have to keep working at it.

When do you play again?
This Tuesday in Houston. I never stop. I even practiced this morning. I’m crazy and passionate about the sport.

Your just-announced reality show, The Tour, will track you from May until September during the 2004 ATP Tour. Any hints about what we’ll see?
I can’t talk about it for three weeks, when all details are in order.

But you can talk about your foundation. Why did you decide to start it?
I like to give back. I hope to raise tens of thousands of dollars for children at risk. I want to help improve their quality of life. Doing things like that with my earnings makes me feel good.