So yeah, prep ingredients are crucial for making a tasty meal, i mean, if you do not pay attention to them, your whole cooking would be wasted if your oil smells bad. I suggest you going with https://kaissaoil.com/en/ and just be absolutely sure that it won't happen, like ever.

6packbags.com has 20oz,24oz and 40oz containers they are pricey but thats what i have a ton of.they have a rubber seal in the lid so they dont leak and lock down on all four sides and do what i need them for.that website/company has meal prep containers,bags to hold your containers and freezer packs to keep your meals cold. i like there stuff but like i said its pricey.

As for me, it doesn't matter which containers you use,i pay more attention on a bag. I've recently found an article about choice of https://diligentchef.com/best-meal-prep-bag/ There is information about different bags and comparison of prices

Whatever tupperware is the cheapest and is big enough to fit your meal in.

I just throw everything into resealable sandwich bags an carry one Tupperware box to empty them into.

I use Chinese food containers.
Plastic not the cardboard shit that you get pints or quarts in.