Yard Renovation

I'm very scared.
I've decided to renovate and change my yard. To do a project beyond what I feel comfortable/capable of doing with my own labor.
I've hired a company to install a couple patios (one for the shower) and and pondless waterfall.
scarey.
I'll post pictures.
and of course, timing has gotten delayed.
4th of july party in just a few days (less then 2 weeks) and just started gravel today.
I'll happen, but what will the mess be?