What is the best way to learn to sew?

I have a suit that i am wearing to my interview in the morning. its one of my favorites but i realized last time that i was wearing it, there was a rip down one of the seams. I am going to buy a needle and thread tonite and my mom and dad showed me years ago but i live in a different state now. Lol. I cant find an alteration place or any where that will take them and fix em up in such short notice. I know how to sew from one side to the other but do i just tie a knot at the end? I just want a temp fix!