Welcome,
You have selected a very good drone to fly as a beginner.
When it doubt, don't touch the sticks. The Mavic Air will hover in place.
This is not to be taken lightly. There are MANY drones which will drift a few feet when the sticks are not touched.
The Mavic Air was my first "serious" drone after alot of failures with toy drones. I could not get any toy drones to hover in place.
Some people say to start with toy drones and work up. I was so bad, that I was spending all my time chasing the crashed toy drone, starting again and crashing.
Once I got the Mavic Air (and first indoor crash) I spent time using the simulator that came with the DJI GO 4 app. This got me familiar with up/down/right/left and rotate without having to chase the drone all the time. I remember reading that part of the App has been discontinued. That's ashame. Since then I got the DJI flight simulator, which blows away the DJI GO 4 app. As a side note: After practice with the simulators, I can fly toy drones now.
I too practice alot in open fields. However, this last week was my first outdoor crash into some cat tails on our pond. It was low on batteries, and the lady was barking at me to land, so I gave it too much "lets get home" stick while going sideways. Going sideways with the Mavic Air is natures way of thinning the herd. No obstacle sensing there.
I was VERY lucky that the
MA hung up in the cat tails and didn't drop into the pond.
Needless to say, I was reluctant to fly again after that experience, so I know the feeling of losing ones confidence as a pilot.
Getting back on the horse is the only solution I can think of, with just more practice.
I find practicing the right to left, left to right pattern, more than the forwards and backwards helps me more.
You will get good advice here.
Good luck with your new drone!