Owners of pet turtles: What kind of setup does your turtle tank have?

I have two small red-eared slider turtles. They’re pretty small, the shells are about 3” each. They’re in a small tank, I think it’s two gallons, without a filter. It does have a heat strip under the rocks, and some pottery that they use to hide under.

A friend who is knowledgeable about turtles was telling me that she thinks my turtles need a filter and UVA/UVB lights.

I am willing and eager to buy them whatever they need, although I don’t relish the thought of spending tons of money. I would like to use Amazon if possible, but first I need some advice on what to get.

If you own turtles or know anybody who does, can you describe what kind of setup they have?