I was worried about the same thing when I went through recruitment. I didn't drink at all freshman or sophomore years, and I knew there were some chapters on campus that were very accepting of that and some that had a reputation. After going through recruitment, I found that a lot of my preconceived notions weren't correct. I did, however, steer clear of the house that constantly talked alcohol to me. I found my home and never once have I felt like I had to drink to fit in. Now that I am of age, I join in. It just wasn't something I wanted to spend the time or money doing before.
I'm sure you will be fine
We're not allowed to talk about alcohol during recruitment, so when a PNM asks about it, I just tell them that my sorority has policies on underage drinking and we accept people who choose to drink or not to drink.