Cheap ingredients like this are basically a free cooking class
3 dozen eggs and a gallon of milk can disappear fast if you stop thinking in terms of single recipes and start thinking in base ingredients. Eggs alone can carry breakfast, lunch, baking, and quick dinners for days without getting repetitive if you use different textures and cooking methods.
I’d split the milk immediately. Freeze part of it if you won’t use it in under a week, then turn some into things with longer shelf life. Homemade yogurt is way easier than people think, and a simple béchamel sauce opens the door to mac and cheese, casseroles, creamy soups, or breakfast bakes. Eggs can become quiche, fried rice, pancakes, custard, egg salad, shakshuka, carbonara-style pasta, or just hard boiled snacks for the fridge.
One thing I learned working in kitchens is that ingredients stretch further when they overlap. Pancake batter becomes waffles. Extra yolks become pudding. Leftover whites go into omelets or fried rice. Nothing has to stay in its original form.
I’d also avoid making giant batches of one thing. People get tired of eating the same casserole five days straight and end up wasting food anyway. Better to prep components and remix them through the week.
Would probably grab some cheap bread, potatoes, onions, and pasta too because eggs and milk become way more useful once you’ve got a carb to pair them with.