Can I use any L2 network for swapping on Uniswap/Dextools?

I want to save up on transactions fee, but I don't quite get how the L2s thing work.

Like if want to swap some eth to some other erc token, can I use l2s instead of the mainnet with high fees? My eth is still on an exchange and I wanna know which network should I use before transferring it.

The L2 option I see on metamask is Linea