Should I cr/ncr any courses as a first year life sci student??

Hi guys. So my 2 courses i have been struggling in are ast101 and bio120. I think you get limited cr/ncr so should i used it in my first year or save it for later like 2nd year cuz thats what most people say is the worst. I also want to go to grad school and they don’t look at your first and second year but i still don’t want a bad gpa(even though i do have a bad gpa but i dont wanna make it worse). Ast101 is an elective and bio120 is a pre req for bio130 but technically not required for my program ig which is neuroscience. Plzz helpp!!