I have a 2009 CRF 230F. What size socket do I

Are you wanting the size of the hex bolt head or the thread size and bolt length? Most oil pan plug bolts are either 17mm (5/8th socket) or 19mm (3/4" socket) bolt heads.

Difficult shifting is typically resolved by clutch adjustment.

.004"-.006" on both Intake and Exhaust. Better a bit loose then tight.

I run 20w 40w. Keeps it loose without the gear box chatter.. Or 30w 50w

change spark plug buddy and try essing around with the mixture screw in pic below

Oil plug is on the bottom of the oil case (under the car). The plug takes a T45 star socket (available at auto parts store to fit a 3/8" drive). You may be tempted by the transmission plug on the driver's side of the car, this is NOT it. The oil plug is on the passenger side and drains straight DOWN. The plug is flat with the case so it is easy to overlook. Look for the round quarter sized circle with a star indentation that the T45 fits into. This is the oil plug. Most auto parts stores do NOT stock the filter (which has a no metal casing) so plan in advance to order one or two before you decide to change oil.