Before you start digging, where you’re going to put your deck, make sure you know what’s below. Check there aren’t any underground power cables, or water and gas pipes. Hitting and cutting into any of these can not only be dangerous but also expensive. Most utilities have a number you can call to find out where cables and pipes are in your area.
The other thing to consider is what’s on top of the ground. If you have a cement slab you’ll need to think about how to remove it before sinking your footings.