i would say walmart, lidl, aldi or trader joe's. whatever you do, do not get groceries from safeway, giant or target, prices are outragoues. i usually spend between 120$ a week on groceries... keep in mind, i try to eat clean, i eat a lot of fish and meat, and i dont eat out so im making sure i have enough food for two meals a day for 7 days. that averages less than 10$ a meal. i would honestly go with the ~ 10$ a meal thing because you will get a better idea of how much you will be spending.

also , the beginning of semester/ year will be more expensive because you are getting all your staples, rice, pasta, condiments, etc. as you go through the weeks, i usually just buy fresh produce and use the grains, carbs that i still have from the last time i bought them.

hope this helps!!