New to Minecraft. Any beginner advice?

I actually just finished the demo. I'm planning on actually buying it tomorrow. Anyway, as I played the demo, I basically just got wood, sand, dirt, and stuff like that. I eventually made a work bench, but I was not sure where to place it… I'm just so confused. I know, I'm completely a noob, but I honestly don't play games. I mainly want to try it out so I can play with my boyfriend because he loves it and we can Skype and play together. He's like… A gaming master and I just… Well suck at games. And honestly, I enjoyed playing the demo, so it's not just because of him. So any beginner advice would be appreciated.