Helping a newb?

I am currently making a small mobile game and need some help. The plan is to have a ball going down the tunnel dodging obstacles and to get faster as it goes. The problem I’m having is not knowing how to make the ball snap to a side when the screen (or button) is pushed. Also with UE4, I am uncertain on how to make the tunnel that has passed, despawn and spawn more further down the line.

Thank you for any help.

Ill be back in an hour or 2 to check the answers.