I’m pretty new to desktop Linux.
Therefore I’m exploring which distributive (or distributives) will be most convenient for me.
So far I didn’t try Arch or Arch-based distributives.
On this week I found information about EndeavourOS in the distrowatch. Then I read a little info in the EndeavourOS site and this forum.
I’m thinking about trying to install and see how it will work on my PC.
Am I correct, that I should start from reading Arch documentation https://wiki.archlinux.org/ ?
First,
Second, never a bad idea reading the arch linux wiki. But if you click the endeavour link abouve there is another link to the endeavouros wiki which is also very comprehensive and suggested reading 
Yes, I know about Endeavour Wiki https://endeavouros.com/wiki/, but it seemed to me that it describes things specific to EndeavourOS, while most basic things (for example, pacman options etc.) are described in Arch docs.
Welcome @Izuchayu_Linux to EndeavourOss.
To install EndeavourOS you will have more info here in wiki and forum then using a based Arch you will learn about it little by little, we all continue to learn on Arch…
Welcome 
I’m rather new here too and also learning Arch (and linux in general) while using EOS and so far it’s been a very good experience.
EOS wiki is more beginner-friendly, but yes, Arch documentation is very complete and rich and (almost) everything there must be applicable to Endeavour, because it’s so close to Arch linux.
And there is an article about pacman basic commands in the EndeavourOS wiki and more
Hi, welcome on the forum.
The wiki isn’t specific on Endeavour since the extra’s we ship are really small. The difference between the Arch wiki and ours is that the basic articles cover every step, while the Arch wiki links back in an article to complete the info.
Hi, welcome on the forum @Izuchayu_Linux…
While it is always a good idea to read the WiKi’s EndeavourOS is a little plainer and easier to understand. Both will help you no matter what Linux you install.
Once you know the basic’s of Linux and the basic commands for that distro the rest will come over time. Just have patients, you will not learn Linux in a day, month or a year! I have been using Linux for over 2 years and I learn something new everyday! Lol
The Great thing about Linux to me and what makes it fun to use is the Learning! Linux is always Learning something new, Always questions and finding the answers…
For Answer to questions, Always and I mean Always come here to the forum and ask! You will never get “RT*M” “Read The ***** Manual here” Yes some will point to a post here on the forum for you to read and will still help even after doing so!
I WILL be the first one to tell you this is the best forum I have ever seen to get help from. There are literally a 1,000 years of knowledge on this forum and someone is always willing to hep! My hero is @ricklinux he has always helped me and the rest are heros too! Just wanted to give @ricklinux a 
for always helping… 
Well I have rambled on enough! Just never be afraid to as a question here if after you do some searching and can not find a answer. You will here…
LLAP
The good thing about the Arch wiki is that its information is generally right for any form of linux. The specifics will change, of course. Endeavouros is very good. After a while, you will probably want to experiment with installing vanilla Arch (you can always re-install endeavouros if things go wrong) using the Installation Guide and following all the extra links. Linux is fun.