Lounges are only helpful on long connections and those are largely when there are delays. With WN, unless you are at some outstation at the end of the line, you really need to stick at the gate because WN may well repurpose an aircraft, load up and go. If you are at the end of the line at an outstation, unlikely there's a lounge.

On standard departures, presuming you have Pre-Check, no real reason to show up early, although with WN's boarding system, you do need to be there before boarding starts.