Hi there Tarah!
My name is Victor, writer and co-founder of Men Skin Care Tips. I was invited by Yedda to answer your question.
A moisturizer, whether day or night, is usually applied at the end of your skin care regimen. By this I mean at the very last, after your face wash.
With Proactiv, the have a 3 step program, which I would recommend following. On their website they mention using it morning and night. So you would apply the 3 step products in the morning and before going to bed. Hope this helps!