Eggs that are waiting for incubation should be kept cool, in a carton, fat end up. You want them to start development all at the same time.
If you are going to buy the cheapest incubator, odds are it will cause heartbreak your first few hatches until you learn how they work. They are notoriously unreliable, but eventually you can get good hatches out of them if they are monitored closely.
You'd be better off saving for a Hovabator, or even making one yourself out of a cooler.
Right now I have them in a Aldi box with the heating pad next to a little water. They are laying flat should they be stand up in a carton or something? Sorry I've never done this and wasn't planning on it since we don't have roosters lol !! So because I should save my money should I just buy a temp gauge and wait till day 5 to check if there are any veins?