A tote bag is a casual-wear bag that can be carried in one hand. A shoulder bag is a type of purse that can be carried on one's shoulder.
Tote bags are usually made out of canvas and are usually larger than shoulder bags. They are also more likely to have pockets, which are great for carrying your phone, keys, and wallet.
Shoulder bags tend to be smaller and more stylish than tote bags. They often have pockets on the inside and outside of the purse so you can carry your phone, keys, wallet, etc., without having them visible through the outside pocket.