尝试比较a列的细胞和b列vba中的细胞

I'm pretty new to VBA, and have been pretty successful in finding the answers I need, until now. I want to take one value in column A, and see if it appears in column B and perform an action when it does find the value and then go the next column in column B. I feel like I am close just not getting something right. I'm pretty new to VBA, and have been pretty suc