How to start learning about automated testing of mobile applications?

Question

Software testing

Good day.
I started working as a tester in a mobile application development company, and it so happened that they were just about to open a testing department and I am the first person in this department, I have never done testing before and I have to learn everything on my own. If with manual testing everything is more or less simple and understandable, then with automated testing it turned out to be more difficult. Googling for general queries and subsequent, newly recognizable terms and names, of course, bears fruit, but is ineffective, takes a lot of time and leaves the feeling that you are a blind kitten that pokes its nose at random in search of mom's tits ... From the results of such a search so far only Appium as a choice as a framework, but there is a severe lack of general knowledge in this area.
Actually, I would like to ask for help in the form of what you can read about:

• how to conduct automated testing in principle;
  
• how to use Appium under Ubuntu (there are detailed instructions on how to install it, but not how to use it further, but I can’t catch up with something myself), or how to use test frameworks on Ubuntu in general;
  

If you know some Russian-language materials - cool! But it will work in English too.
Thank you.

Answer 1

Appium has examples on github for your language. Look.
Appium is not a complicated thing. Works on the Selenium protocol. Adds custom stuff like ui automation (ios)/ ui automator (android) selectors. He also knows how to run the simulator and put an application on it. Perhaps that's all.
> how to conduct automated testing in principle
Very simple:
* Write a framework.
* Write tests.
* Raise the environment for their execution.
* Drive tests on schedule and constantly write new ones.

Answer 2

how to conduct automated testing in principle;

write code