Just bring your walking clothes and stuff. Most food and other gadgets you can buy at:
ICA, Willys, Konsum, Lidl, OBS = Food stores. The big ones even have DIY departments.
Granngården = Farmers supply center. Usually have nice outdoor clothes as well.
Ö&B = Used to have military surplus, now just an ordinary low price store.
IKEA = You know.
Bauhaus, Rusta, Harald Nyborg, Jula, Clas Ohlson = DIY stores
Try to find a big shopping center complex and do all your shopping at one place on preferably a rainy day.
Did I miss anything?