Portfolios and composite cards are used by models and those doing commercial print. Different cities want different kinds of photos. Take time to find a photographer who knows what that demand is and who is recognized by the agents and casting people. Moreover, do not pay to have your picture put in a book by someone who comes to your hometown and says you ll be seen in all the major markets. Agents want to contact and see you , not a book.
Training is necessary.
Know who your teachers are and what their experience is. Investigate the schools available, audit if allowed, talk to other students and to the agents who represent you. Again, different markets require different techniques. Learn the business as though it was any other. You must learn how to be interviewed, write cover letters for your photos, follow up your sales pitch, be dedicated and persistent, and take it step by step.