I am doing lasers but not hitting the asteroids successfully.

①You might unable to lock onto the targeted asteroid.

Aim your head towards the asteroid you want to target and confirm that it is surrounded by three yellow triangles. When in this locked-on state, doing the laser will hit the intended asteroid.

②Not get use to the controls of the VR game.

Continue playing the game for a while and observe until you get used to the controls of VR games. Alternatively, turn off the dichoptic mode to get use to the VR world.