Hello everyone, this is my first post on the forum.
For some time now I have been very interested in this environment, I would like to create a 3D game with an isometric view, but I don’t know where to start.
Survival RPG game, the main screen is a map with locations to which the player moves after pressing them, one of the locations will be the player’s base, in other locations the player will be able to exploit the game world, fight opponents and collect exp.
I don’t know where to start, could anyone recommend some courses or books?
I will create models for the game myself in Blender, I have a lot of time and patience and creating such a game can be an interesting experience 
I am counting on your help and understanding, thank you in advance and best regards
theres quite a lot on youtube, but dont fall into tutorial hell and expect all things to have a tutorial, and tell you what to type (please). Look up all the functions, look see what they do, why they picked those specific options etc. If at the end of the tutorial you have code and you wouldnt have written that code now with your knowledge, either, it was not a good tutorial, or, you didnt make the most of it. You should be filling your head with things as you go.
In essence, isometric is a view not a way of being, so, dont discount tutorials not set in that view.
Start by making plan, can use brain storm, split your project in smaller parts, like:
() Player Movement;
() Main Game Loop;
() Combat System;
() Inventory System;
() UI;
() Particle Effects;
() Sound;
() Music;
() Marketing;
Write as many as are needed to make your game working!
Then assign prioritise to them, let say:
(A1) Main Game Loop;
…
(F3) Music
…
(G7) Marketing (indie devs curse)
Nice way is also forcing yourself to limit amount of time you can spend on each part… so you will not abandon your project after 300+ hours spend on character modeling, without working at all User Interface (UI)…
Then do research about part which you work ok this day… and make small TODO list for it… and kill it!
As @bugfinders mention above do not felt into tutorials hole too much… always work with tutorials OUTSIDE of your project… and after completing tutorial implement only solutions actually needed / fitting in your project.
Another small one… start by making nice folder structure (like Animators, Animations, Models, Materials, Prefabs, Scripts, Sounds, Shaders…) and keep your things in order…
Hope you will find some of above information useful.