The Beaver is a tail dragger (also called conventional gear). If you suddenly apply throttle you will cause a ground loop. Slowly and evenly apply throttle. Using up elevator will keep the tail wheel in contact with the ground until the rudder becomes effective will normally help. Release the elevator and as the tail comes up you may need to apply a little down to keep the main gear in contact with the ground until flying speed is attained. Learning to ROG (rise off ground) is one of the most pleasant moves to learn. It is not the easiest though and that is why trainers are generally tricycle gear.

If the plane is not tracking in a straight line it makes gaining airspeed more difficult. Check to make sure the tailwheel throw is at minumum. If there is no tailwheel it will make it harder and asphalt will be much worse than grass. It may be difficult with the plane discussed here as it is electric and somewhat small.

EXCAP232