Its really not hard at all. My current set up is a 10g aquarium with a pump (not a filter) to keep the water circulating. I have lots of leaves for them to climb on (pothos) and large river rocks for them to climb on. My water is 2-3 inches deep and I do a partial water change once a week and a total cleaning monthly. I also have a mystery snail to help with algae.
Your set up kinda depends on what your specific toads like. Mine prefer shallow water, some like deep, some like almost none (a bowl). I used to have partial water partial land but my toads just dug up 'the beach' and turned it all into water anyway. I made the land portion out of piled aquarium rocks and covered it with a inch of moss. So really its up to you. Whatever makes your specific toads happy