You may want to take that LR and sand right back out again if you plan to dose copper. Cycling isn't necessary, but you should be prepared to do water changes, and watch your ammonia levels closely. If you are dosing copper, get a seachem badge instead of testing with a test kit; it can be difficult to get accurate readings when dosing copper.
Generally QT are more sterile if you plan to use medications, because rock and sand can absorb them. Usually people add some pvc fittings to give the fish some hiding places