High School Senior & Nursing!

Hello!! So I’m very confused with the admissions process and I would really like some advice and help! I was looking into University of Oregon and OHSU but it seems that I would have to go to University first before going to OHSU?? I’m very confused with this because Uni of Oregon doesn’t have nursing so I don’t know how I would do the perquisites for OHSU. Such as what my major would be for Uni because I would have to do the perquisites but I’m not sure which major to choose from. My explanations are probably very confusing but yeah I have no idea what I’m doing and how i’m going to apply and how this all works... I would really appreciate the help 😭😭