A front of something in a dream is basically the first thing that comes to mind when you think of something. It means if there is a front in a dream it means that the person who saw it is going to have success.
A front in the literal sense would be someone walking in front of you, or as an analogy it would mean somebody or something being there before you. The phrase can also refer to something like a front door, where there’s been some sort of obstacle preventing progress, but now they’ve come through and are viewing what comes next.