roll-a-ball tutorial question

hello, i am a new user to unity, and i have been following the roll-a-ball tutorial in order to help me get started. however, i have run into a problem.
i do not know how to get the ball to roll. after following along in the video 02.moving the player, after finishing the script, i have hit a dead end, in which the game starts, but i have no control over the ball. i have pressed every key on my keyboard. i have not been able to move this ball once. the speaker talks about pressing keys set up on the input manager. i do not know what the input manager is.
i would very much appreciate assistance on this matter.

did you attach script with the ball??

yes sir, i followed the video perfectly, attaching the script to the ball. just now to double check my work, i have re-created the scene the exact way the speaker has, by copying and pasting the sample code provided, and my ball is now rolling. i will chalk this up to a unseen syntax error. thank you for your time.