first off, wherever you go, take the kallah with you so she can choose patterns, appliances etc.
bed, bath and beyond is great, they have absolutely everything and they have 20% off coupons that you can sign up to get. (and a little secret- they accept expired coupons! so dont throw them out!)
you can also try jcpenney and macy’s home collections, often they have very nice dishes and kitchen things that are on sale, especially now during their holiday season. it might be easier to find sets of 8 or 12 dishes in the jewish stores, but other stores sell a standard set of 6 and i just bought 2 boxes=set of 12. you can get nice corelle dishes for milchigs as well.
for large brand name stuff (cuisinart, bosch, kitchen aid, calphalon, blender, pots/pans, toaster, microwave) etc. i’d do some research before you go shopping, because often you’ll find a cheaper price online and stores will often match it
mazel tov! happy shopping!