I've seen solo reasonably between 15 - 35 hours, rarely is it done at 10.

Rudder should be used to stay coordinated until short final (ball centered). During the LDG, use the rudder to keep the nose lined up with centerline.

With no crosswind, you use minimal aileron inputs just to keep the wings level and the airplane in the middle of the runway.

With a crosswind, you'll typically setup in a side slip on short final. You'll bank into the wind enough to hold the airplane on the extended centerline without drifting. You can increase/decrease the bank as needed to keep the airplane on the centerline. You also use enough rudder to keep the nose pointed straight ahead so you don't land sideways. Set the bank first because the amount of rudder depends on the bank (the bank depends on the amount of crosswind).