Hey,
So you can start by using these for reference first, and you can type questions and often they will pop up.
http://help.autodesk.com/view/MAYAUL/2018/ENU/
If you provide pictures and videos, it will make it easier to help too.
There are a lot of resources here too:
https://knowledge.autodesk.com/support/maya/learn-explore?sort=score
Here is a great resource for learning about Maya and 3d modeling, etc.
https://www.academicphoenixplus.com/
However, I will be honest, it is better to take a class like LinkedIn learning, or Pluralsight.
With Pluralsight, I am taking a character building, dynamic particle, environment building, and Arnold classes through them. Although much of there content is outdated and you have to reference back to the 2018 manual to see what they did with a tool, etc.
However, you can take an intro course their them or LinkedIn, or Lydia for a trial period and learn all the basics, much better than trying on the fly.
The best bet is to find the fundamental videos here, go over them, then do one of the fundamental course above to get a varied look, that way you get more than one way of doing a lot of things. 3D modeling leaves a lot of ways to accomplish similar tasks.
A lot of great resources on shading, lighting,, and rendering using Arnold here" https://support.solidangle.com/dashboard.action