I unlocked a Pistol for the scout called "The Winger", Is it good? Or should I trade it?
(For future reference, you didn't unlock anything, it's a random drop)
Most weapons in TF2 are as good as any other, they're just useful in different situations; look over the stats and/or its page on the wiki to find the best way to use it
There's no need to get rid of anything immediately unless there's another item you desperately want to trade for, it's good to keep at least one of every item when you get it to make sure you're ready for any situation