Bm can be kept in the fridge for 2-3 days, so your 1 day old milk will still be safe for consumption. To be safe, you can do a smell and taste test first (taste test is more accurate as the lipase in your bm do affect the smell after milk is fridged/freezed) . If it taste sour, best to discard or you can use as milk bath.
For storage, try to lay it flat without stacking or anything near it.