Help with Path constraint

[GBREAL]

I been two years now that i had this program and figured out that.....I have no modeling skills what-so-ever

( I should have known sooner when I couldn't model the basic flour sack ) So i decided to work with what skills (I thats what you would call them ) in animating. The project I Am working on is going steady right now but I am having some trouble. Itrying to have one character walk to a certain point at a certain time but can't seem to get it right. How do I do this