Welcome from another Newb.
First thing to do is register with the FAA. Very simple process. With that registration you can use the number provided with up to three Small Unmanned Aerial Vehicles. The rules for flying are right on the registration pages.
Download B4UFly to see various restricted zones for flying. Altitude Angel is another good resource. And with the later versions of firmware in the Mavic it will warn about No Fly Zones NFZ.
Lots of info here and more than you can stand on You Tube. Start in Beginner mode and learn as much as you can about flying the Mavic. Don't worry much about the pictures and video. Move from Beginner mode to regular mode when you are sure you can fly the Mavic where you want it to go, AND get it back. Return To Home is a lifesaver. Once you have flying down and are comfortable with the controls and behavior of the Mavic. Begin to do some photography and video shooting. Don't worry about the first ones. Just keep practicing. There are settings for everything in the DJI Go 4 application. Check out specific You Tube vids as well as asking here for advice if you get confused.