Guyster
Hello & Welcome to the Forum!
Oh! The pain of used track.....
Okay, you purchased a "load" of used track off an online auction site,
first thing you need to do is clean the connector pins & holes they fit into, your Emory cloth will work for that.
I'm guessing that you have tubular track, so after cleaning the pins & holes, you'll want to make sure the pins fit tightly into the holes of the joining track. You can use a needle nose pliers to crimp the track below the holes and pins, if you don't have a pair of track pliers, to tighten/crimp the track.
You don't say if you have rusty track, so will just recommend your basic track eraser to clean your rail.
A green scotch bright pad is used by some people, but if you use one to clean your track, do it somewhere that the dirt/mess/crud that you will create does not annoy "She Who Must Be Obeyed" (SWMBO).
DO NOT DO IT ON HER CARPET, KITCHEN TABLE OR ANYWHERE ELSE SHE MAY BE UPSET ABOUT!!!
Do Not use Steel Wool to clean you track, that creates little bits of dirty steel wool that can & will ruin your locomotive. Remember elementary school science class where they spread iron filings on a piece of glass and moved it about with a magnet? Think big magnet shaped exactly like your locomotive...........
You will also want to make sure your wheels and pickup roller or slider, which ever your locomotive has are clean.
You can lubricate the pickup roller with a small drop of electrical conductive oil on each side of its' axle. Also good time to lubricate your locomotive & axles on your cars, use small drops of a light plastic compatible oil.
You can use heavy aluminum foil to clean off some of the oxidation on the rail head, leave the rest..
Natural weathering, ya' know.....
Some of my track is 75+ years old and works just as good as the brand new stuff, it just isn't all shiny..
Happy Rails!
Dave