Help with making frozen dinners..

I find that robust, soupy meals like lentil soups or bean chilis freeze very well. I just seal in plastic bags so not sure about air exposure. You can defrost overnight in the fridge, yes. I would say that certain green veg like broccoli and asparagus don’t always freeze well (they can sometimes end up mushy).

Soups and stews freeze well and can be frozen in those deli style cup/half quart/quart containers that you get with take out food.

I don't tend to freeze ready to serve plates (that is, protein, veg, and starch in the same container) because it makes it harder to find a suitable container and it makes reheating difficult. Rather, I'll freeze and reheat each item individually and then plate together after they've been reheated.

Food saver or zip lock bags are really nice because they can be used for a wide range of foods and most of the air can be removed regardless of what you're freezing. You don't need specialized equipment either. You can squeeze most of the air out of a zip lock bag by submerging it in water. Give it a google.

Frozen food can be defrosted ahead of time but the best thing you can do to reheat your food is to use a pot of barely simmering water. A water bath provides a gentle heat that will bring your food back to temperature without risk of overcooking or drying out. This holds especially true for meats but it's pretty universal across all food types. And because water is such an efficient conductor of heat, it's also faster than almost every other method. No defrost required. The ability to reheat in water is another reason that freezer bags or deli-style quart containers are so nice. No air in the container helps to avoid freezer burn, but it also makes it really easy to reheat in water.

Freezing tends to collapse the cell walls of vegetables if not done in a commercial blast freezer so it'll be hard if not impossible to freeze anything you want to stay firm or crisp.