What size of tank?

[erik.m]

So i have been looking into getting a smaller tank in my place and make it somewhat special.

I have always wanted to have a saltwater tank, with 1-4 clownfish, an anemone, and maybe some other pretty coral. My budget is around 500ish..

What size is around 20 gallons(LxHxW)?
what would i need to start off? What should i get/stay away from?

Thanks,
Im excited but kind of nervous lol

Erik