The trucks are the metal parts that attach the wheels to the deck. If one truck is tighter than the other, it can cause the skateboard to turn in that direction. Check the tightness of both trucks and make sure they are evenly adjusted.
It is usual practice to clean bearings with alcohol or a citrus cleaner; the latter is safer but more likely to leave residues. Since a citrus cleaning is water-based, you must quickly dry your bearings in order to prevent rust.
You can clean your grip tape on a skateboard or longboard with a portion of sanding belt cleaner or the entire block. Holding the sanding belt cleaner, begin section-by-section rubbing it on your grip tape from top to bottom in a straight line. But pay attention to the locations of the bolts. Gently wipe these areas down.
