Do you need a quarantine tank? That's the firs question.
Other than that, yes, you can use a plastic cotnainer as a quarantine tank without problems
It might be better though to get a 10 gallon one, since the fish need good water quality, especially if they are sick and need quarantining!
You set it up like a normal tank, you can add a plastic plant and maybe a big pipe or something as a hideout so the fish will feel more secure and home
Substrate isn't needed at all!
Then you just add some fish food to the tank (without fish) and let it cycle in peace! Or you could take water from your main system and fill the new tank with it, and it should cycle much faster!