Should I take the practice for my practice SAT or go and visit Columbia University in NYC?....?

So I have PSATs on Wednesday and there is an optional study cl for the PSATs after school that my help my grade for them but my sister is going to visit Columbia University tomorrow and I can come but miss this cl to study for the PSATs the next day and I might be too tired for them. But I really want to go to Columbia and it will inspire me to do well.