Check out refilleries in your area if you have them. You'll pay a bit of a premium, but they are usually high quality, local goods and low/no plastic. Usually stuff like soaps, personal care, that sort of thing. They are a godsend if you or someone you know is allergic to fragrance(s) too, as they have a variety of unscented soaps, dishwasher detergent, etc.
And, you get to bring your own bottles to refill, which is kinda nice if you like to buy in bulk.
Sugar is gonna be hard to find, since it has to be imported, unless you have sugarbeet farms in your area.
Fwiw, being best friends and living together isn't that far off from dating. It's so fun to live with your best friend too, like all the sleepovers, campouts and hangouts combined :D (if you can't tell, I miss living with some of my best buds in uni!)
Sounds like a fun living situation, even if it did have its normal ups and downs. Sometimes one bedroom can be kinda a bit much, haha.