I have just passed through the "initial noobie stage". I would suggest that you:
1) download the manual and read it; familiarize yourself with the basics (e.g. where all the buttons are, how to initiate RTH, how to "pause", movement of the camera, video button, etc.
2) watch the videos on setups and "what not to do's". (setup things like RTH height, max height, beginner versus normal, versus sport modes)
3) figure out your startup routine (remember to include removing the gimbal guard). Have a look at the suggested checklists. Prepare your own and write it down so you have it in the field and can refer to it.
4) take the props off, and start the Mavic inside with a view to outside so it can get a GPS signal. This will allos you to do the setup (the Mavic has to be powered on and connected to the remote control). You can also run the simulator. (this is good for about 10 minutes, but will orient you to the controls. Try flying figure "8's" - clockwise and counter-clockwise.)
5) for your first flight, set a plan of what you want to do (and what elements you want to test to get comfortable with (in case of danger) e.g. RTH operation, pause, flying a figure 8, manual landing
6) as others have said, be cautious, but not afraid. The equipment will do what you want it to. Take everything slow initially. Fly higher than you think you want to.
Have fun!