Hh ny3d1,
There are no real basic questions (i.e., “simple”), as they all represent parts of a more advanced set ups. Never underestimate the power of basic things. Without them, the development is tremendously slowed down. I mentioned this as I want to give you the idea to ask whatever it is, I do not see those as basic, they are essential for the progress one wants to have. There are no short cuts …
I would suggest to go through the “Quick Start Guide”:
https://www.maxon.net/en-us/support/downloads/
go to “Updates r17” and there documentation.
There is a enormous value in this little book. Scene files will do even more for you.
Tutorials are also in the Help Content of the application it self.
To answer the texture question, well, here is a one minute clip to get you started, but texture and material is a larger theme, and as mentioned—essential.
https://www.amazon.com/clouddrive/share/DzSK8ayoenF6SmcDpJQVi2ivAdCQCUWsz8pA7vUvHOW?ref_=cd_ph_share_link_copy
Specular or Glossy look?
All the best