Since you have already test ridden the bike, then you know that it fits you and rides well. If it pulls to one side or the other, you might have bent frame or fork issues.

Lubrication is far more important and challenged than you might think. Oil, and more-so grease, loose their ability to lubricate with the passing of time. I have opened bottom brackets that had nothing more for lubrication than rusty dust. One bottom bracket even had a dweller inside...



The headset is fragile and should be properly greased and adjusted...



The wheel hubs and the mentioned bottom bracket should be greased and adjusted...



After that, spend away on cables, bar tape and the like. But don't assume the grease is good to go, because it is possible that it already went.