First, recall the following conversions between units:

Convert the capacity of each container available in the store to gallons:
2 pints of milk

2 quarts of orange juice

16 cups of chocolate milk

32 ounces of lemonade

Add up all the capacities to find the volume of beverages of buying 1 of each container:

If Julius buys 2 containers of each beverage, then the amount of gallons will be twice the amount of buying 1 container of each beverage:

Therefore, the amount of gallons of beverages that Julius bought is 4.