Hey KeithRob. Since the question is open ended my input is very generic.
Personally, I just started using an airbrush about two years ago and I'm still learning how to work with it. As with any skill, fluency comes with practice, and time. Lots of time.
If you haven't seen them yet Aaron Skinner did a great introductory video series called Airbrushing with Aaron. I found them to be very helpful when I was just starting. They helped me avoid some beginner challenges and learn how to fix others I hadn't.
https://finescale.com/search?q=airbrushing+with+Aaron
To help build comfort and familiarity with your airbrush there's also a practice exercise I read about somewhere. I found it very helpful. It's boring, repetitive, and a pain to do, but it helped me learn my airbrush without having to practice on a model.
You just need some scrap cardboard (glossy side of cereal boxes works great as simulated plastic), a ruler, and a marker.
On the cardboard draw out a grid of 12 dots that are about 1" apart from each other. I'd suggest prepping two or three of these grids ahead of time.
Then starting horizontally use your airbrush to connect the dots. Focus on keeping your distance from the cardboard consistent along with the amount of paint coming out, and your line as straight as possible. It's a lot to keep track of.
Once all the horizontal lines are done start connecting them vertically.
When you're done you should have a grid of 1" squares.
Repeat this with the other two grids you prepped.
If you can make it through doing this exercise a few of times, by the end you should be rewarded with the sight of nicer looking squares. Along wit greater confidence in the control of your airbrush.
I still do that exercise every now and then to keep me honest.
Regarding the airbrush your using. I recently ordered a Master airbrush from Amazon as well. It's my second airbrush. The Master airbrush isn't a bad brush. It lays down paint well and I mostly use it for priming my models. It could just be the one I got, but I find it takes more force to operate than my Iwata Neo CN.
In comparison my Iwata is practically effortless to operate. The extra effort it takes to work the Master may impact consistency as well. The more tense we are, the more fine motor control lost.
And if possible, I'd highly recommend choosing one paint manufacturer to airbrush with. At least to start. There are so many differences in how each paint works that it makes it hard to tell what problems may be due to technique and what are due to changes in the paint's properties. Getting familiar with one paint means when trying a new one, it can be a little easier to figure out where the problem may be.
Apologies for the long winded response. Hopefully a little bit of it is useful. Good luck and happy airbrushing!