Since Im able to access that site for free, Im thinking to learn more about Photoshop, C1P, and Premier Pro for better skills but I wonder if it's good to have most skills to use those programs.
I've found them to be invaluable in the past. They are very thorough with their courses.
What do you mean by saying "but I wonder if it's good to have most skills to use those programs."?
You should be able to get all the assistance you need from the various Lynda courses.
Just in regards to retouching, which you are going to need to know how to do really well, they have 48 different courses available covering Photoshop, C1P and other programs.
For portraits, they have 72 different courses available.
They also have courses on running a business too.
Good luck with it.
Since Im able to access that site for free, Im thinking to learn more about Photoshop, C1P, and Premier Pro for ...