أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
Taking a course then using a manual and by trial and error
Just like any tool, photoshop is about trial and error.
but you need to think of what you want to do with photoshop ? Is it creating pictures with photo collage ?
Is it modifying pictures like enhancing models ?
Or simply making your pictures look more beautiful.
Maybe it has nothing to do with pictures, and you want to create the most kickass logo ever. Each function is different.
Step1 : Know what you want to do.
Step2: Google your question. "How to make the skin look smoother" "How to add shadow to a logo in photoshop"
Step3: Practice, practice, practice.
You didn't learn how to walk in a day, the same applies for softwares :)
Good luck
Download, trial version, Practice with tools and Brushes, learn via online videos like Lynda.com