Breastfeeding/pumping question

Hey ladies FTM here with my newborn son who I'm madly obsessed with💙. We are exclusively breastfeeding. Having some issues. He has a great suck but his latch could use some work I think because he's mostly only getting the nipple and my nipples are raw. I plan on seeking a consultation but any tips on how to make his latch better or how to know his latch isn't correct? Also, my breast pump is coming in two days and was curious to what is referred to as a "let down"? I was thinking of almost going exclusively into pumping for him because I'm in so much pain with the feelings but not sure. How did you mommies balance out between bottles & boonies during the day. Also I'm not working so won't be pumping for that. More so pumping for my BF and mom so they can feed them as we'll as being able to go out and run errands longer without excusing myself in public which i hate.