I would say a 5.5 - 10 gallon tank would be minimum.
They need a heater and a filter.
Once a week 30% water changes. Treat with water conditioner.
Feed frozen bloodworm and a high quality frog pellet. They have poor eyesight, so keep that in mind. You may need to make sure the food falls to the bottom.
I wouldnt house them with fish personally, but many do.
They are escape artists, make sure your top is secure.
Many can develope bacterial infections, so be careful who you purchase them from. Ask them if they have had a lot of casualities. Thats a bad sign.
My father bought me an albino clawed frog (thye get much larger than the dwarf version) as a child and he lived for 13 years before hopping down the drain. I was very upset.