one referral

I got a referral for not coming to my first period of the day, a teacher saw me out with a friend getting breakfast. we took a zero on the test that we missed and both got our parents called. when you log onto portal and look at referrals it comes up but says type A talked to parent and thats the only thing that happened. This is my only disciplinary action in all 11 years and I have always gotten great grades, am number 12 in my class, and extremely involved in extracurriculars. How much will this effect my chances of getting into good colleges?

No. But it would be a mistake to continue to do it.