biology classes

I am currently failing biology and my biology lab class. Its stressing me out and i cant seem to grasp the material. I really want to pass with a B at most. I dont want any C’s but if it happens thats okay but i plan on going to grad school to become a pediatric nurse practitioner and i heard B’s in science courses doesn’t look good to them. Its either i can bring my grades in both classes all the way up or i quit and change my major. Anyone have any study tips especially for science?