Well, first of all, there is clear information when you select the gameworld that it's an advanced gameworld. You for sure had seen screen like this:

Why don't you practice on Quimby which still has 86% of slots?
The server will be going on for a few more months, you can practice and learn... and most of all, it has new dynamic turnaround settings which you should practice because the new launched gameworld in the future will have those dynamic turnaround settings.
http://quimby.airlinesim.aero/app/info/airports/2745
You will not gain much progress if you just read, you need to read and practice. You do not become a swimmer by watching videos and reading about swimming. You need to practice. You can watch how to swim, but then you need to try it on your own. You then go back to instructor for help, and then practice upon the feedback you get.
Quimby might be actually the best server for you, because of its limited time. This means that most advanced players do not take it "seriously" and only set up airlines to try new things, such as dynamic turnaround times, but they do not spend time and effort to become the "biggest/largest/dominant" there (with the exception of some Chinese players, but they are a different story, and you are not interested in China anyway). What this means is that you will be competing against newbies and medium-advanced players, but not against the "crushers" - they simply will not spend that time and effort on a server that will be shut down in a few months.
This is your best opportunity to learn AirlineSim. And you must part with some of your "ideas" and "wishes". I put it a different way: we all are dreamers. Some of us start our own businesses. We all have dreams and ideas of what that business should look like and what we want to do. Most of the times, though, in real life you find out that the way you imagine things will work, is not the way they will work. The dreams you had about how your business should look or what it should do, must be changed dynamically, rose-colored dreams abandoned for a grain of reality, and adjustments made in order for your business to survive. A person may dream to open the best XYZ-cuisine classic restaurant in town because his own family recipes are very tasty and delicious, only to find out nobody comes in to dine, and he has to abandon the dream to have a classic romantic restaurant with waiters uniformed in white suits, to transform it into a cheaper faster-moving food-on-the-go outfit, so he can survive. Just an example.
I am entrepreneur in real life, and I have found out over and over, that your ideas you have when you start a business are not the same thing the business will look like/be operated after you gain some experience, and are faced with realities of the market. I do not know what is your profession, but if you have ever studies business-related subjects (or even law) you must understand that things are very dynamic and very rarely they turn out the way you want them to turn out in the beginning.
These are the words of encouragement, not of a critique. These are the words to help you understand that you need to adapt to the realities of this simulation, and when you do, you can enjoy it tremendously. The simulation will not adapt to you, you must adapt to it, and to do so, you must let go of some of your ideas or concepts you have envisioned. I can assure you that if you are challenge-seeking, you like to discover new way to do things, analyze and implement business models, etc., you will not find a simulation with even a close resemblance of AirlineSim.
I recommend you start on Quimby, learn and practice. The decision is ultimately yours.