Breastfeeding

Ladies, I’m expecting baby #2 in a few weeks (10/10). I struggled with breastfeeding with my first- low supply, barely pumped anything, he wasn’t gaining weight- so started formula at about 3-4 weeks. I’m wanting to try again and be successful. Is there anything I can do NOW to prepare and get ready for successful breastfeeding? First time I took the mother’s milk capsules, drank the tea, drank water... anything?? Also, does size of breasts matter? I don’t have large breasts (B cup) and they haven’t changed at all during this pregnancy... thanks for your help!!