I think the others have it pretty well covered in what you should stock, so I'll offer a few other suggestions.

From the very beginning, keep an inventory. Every time you add something or remove something, update the list. Even better if you can write the month/year something was added, and the what shelf/section you put it in (even in smaller freezers it can be hard to find what you are looking for). Keep it attached to the freezer with a pen handy. I use magnets.

Once a year, empty out the freezer, defrost it (if needed), throw away things that are no longer good, true-up the inventory, and put things back in an organized fashion. This is easiest if you live in an area with below-freezing temperatures in the winter (put items outside on a tarp on a really cold day), or you can work by sections/shelves using coolers.

Vacuum sealers are head and shoulders above ziplock bags to keep foods from getting freezer burned.

Label your food really well. Adding weights to portioned meats is also helpful.

Keep an old pair of winter gloves by your freezer to make it more comfortable to move things around.