There are many good tutorials online, most software companies will have community areas on their websites, with some professionally produced tutorials for their users. This is a great place to start off with, as they will promote good workflow and have galleries of work for you to aspire to achieving. It may also be possible to talk with the artists that created them.
You can find some very good affordable tutorials/courses, by industry artists on sites like Gumroad, Pluralsight, Lynda, CGMA. There are also online full ‘tutor lead’ courses, which offer valuable feedback as you progress through the course.