Weaning question

My son nurses 4 times a day. He will be 1 in two weeks and I was thinking of starting to wean him gradually, dropping one feeding a week and just seeing how it goes. So my question is, when we drop a nursing session do I need to replace that session with whole milk? Or do I wait until we stop breastfeeding completely to introduce whole milk? Sorry if this is a dumb question, this is my first and my pediatrician isn't very informative. Also kind of nervous about introducing cows milk since cheese tends to give him hives, and he may have a peanut allergy as well so probably couldn't give almond milk either..any alternative (affordable😬) suggestions would be appreciated😊