Moving my character around.

I have been having an issue with moving my character Steve. I started yesterday but I was told that when I move my finger on the pad on my laptop that my character would move. My character moves but only when I don't walk. I have ran from mobs but I still get killed because I cant move my character when I walk or sprint. I don't know how to reproduce the issue because I just started. if you can help me that would be much appreciated greatly. I don't want to be killed for this reason when I'm far along in this edition of the game. Please help me.