Weaning a 1 year old

Bre • Had our first baby in January 💖

So my baby will be one in a couple weeks and we are starting to think about weaning. We aren’t in a hurry to quit but I’m trying to be prepared, I’ve read that at first you should mix breast milk and whole milk gradually increasing the whole milk. I don’t have very much store so I was thinking of pumping at night before bed just to store some for when we do decide to start weaning. Will this cause a problem?