No fish would die right away if they are properly cared for. Most people set themselves up for failure because they do no research prior to purchase. You are going about this the right way asking questions beforehand and giving yourself the best chance of success.
What you need to think about is how much time, money, and space do I have to devote to this fish?
All aquariums need to be maintained weekly by performing weekly water changes of about 25%
The simplest set up would be to buy a 2.5-5 gallon aquarium, a gentle filter, and an aquarium heater for a single male Betta.
What I would do is something simple-
A ten gallon aquarium is large enough so that it can't be knocked over accidentally, and gives you more options on what fish to buy.