Breastmilk is based on supply and demand. The more you latch your baby, the more your body tells itself to make more breastmilk. Of course, without hard work, the supply can also be affected.
Pump and latch, pump and latch. Latch and do not stop latching. Every 2-3hrs pump out your milk and store in the freezer, keep a stash of your breastmilk. Keep in milk storage bags in amounts of 60-120ml for a start and lay them flat to save space on the freezer.
Latch on demand, 5-10mins each side. Depends how long your baby can empty your breasts. The supply will gradually increase, it won’t be immediate so have a lot of patience. You may need to wake up in the middle of the night to pump if you want but day time, make it a routine and put alarms for pumping. It’s tiring, your nipples will be sore, will crack but after a while it will be ok. Apply some nipple cream that are safe for babies. Massage your breasts before every pumping session/latch to stimulate the ducts so that it won’t be clogged cause you don’t want mastitis to build up. It can be super painful. Your breasts will feel rock hard solid and even with the slightest touch can make you cry. Watch out for hard breasts ok.
Every time you pump/latch, drink a bottle of water because breastmilk is made out of 88% water.
Good luck and hope you can be on the BF journey for as long as you want.