If you were suspended in high school Princeton will know right?

Princeton University's admissions process considers a wide range of factors, and a high school suspension would likely be reported on your application, either directly by the school or if it comes up during the recommendation process. While it's not an automatic disqualification, it's certainly something they'll take into account when evaluating your application alongside everything else. They'll want to see how you've addressed the situation and demonstrated growth and maturity since then.