Local gun show is good. Usually there are some who have survival food and emergency medical supplies.
http://bulkammo.com is good website
As far as bulk food, I suggest start with what you already eat and just get more. That is how I started. Get whatever canned food is on sale but more. I budgeted $10 a week when I started out. That is I bought $10 extra food each week.
If you’re in an apartment, then I’m “assuming” you’re in the city wehre you must rely upon someone else to provide the water and electricty. In that case, even with limited storage space, I’d go with regular grocery store canned goods rather than dehydrated foods. Canned goods don’t require water and the liquid they’re packed will suppliment your water needs. Be creative in your storage. Under the bed, under the couch and under and behind the dresser. Buy furniture that already has drawers or cabinets. Rather than an acrylic coffee table, get a trunk. Those end tables with just a top and legs are a waste - get ones with drawers and cabinets. Pull the bed a foot or so away from the wall and build a shelf unit behind it to place a lamp, a book and your glasses. Under that shelf is a ton of storage.
The plastic milk crates that are a 12” cubes are stackable and will hold 32 (yes, 32!) regular 15 oz cans. They can be covered with fabric and used as seating or as that coffee table or stacked several tall and used as a plant stand with no one the wiser.
Buy your ammo locally and pay cash. The Feds are monitoring online purchases.
My two cents about ammo. Use www.ammunitiontogo.com if you must. They'll ship anywhere and have a good selection and decent prices.
But the best way to go is to bring lots of cash to your local gun show and buy it there. That way you can avoid leaving a paper trail whilst buying large quantities for stockpiling.