"Boob Man"

So! I have this awesome little guy that seems to love me for my boobs 😂. He's 11 months old tomorrow, and I'm going to continue nursing as long as he wants. My question is this- once I DO wean him from my actual breast (he is SUPER attached), somewhere around 18 months to 2 years, I would like to continue to pump for a while and give him MY milk instead of cow's (or almond or goats, etc.)... My issue is, he only nurses straight from my breast. He gets plenty and is healthy but I can't seem to pump much.

How do I go about getting a good pump supply once he is no longer on my "bah bah"? Do I just start pumping as much as I can and build up or is there a trick? All comments/suggestions welcome, just please be courteous to one another- THANKS IN ADVANCE!!!