NO matter what branch of show business, or for that matter, any other career, the bottom line is that you've got to start somewhere. Where is that "somewhere" when your chosen profession is acting, singing or modeling?
Probably with learning the essentials.

What does it take to become an actor or actress, how do you find a talent agent, what's a casting call, and what is an audition?

One of the things that probably needs to happen, is to be where the chances are greater that you're going to find work.

You may like Podunk Minnesota, but the chances are quite good that you're not going to find acting jobs there, or acting jobs that will lead you into bigger or better parts.

Chances are that your selected career is going to require a move to a more major metropolitan area, if not to the city itself. As you build a resume you can and most likely will have to work in other areas that have good film or live theater communities but the end result will be that a larger city is in the cards for you.

You will also need to take some kind of acting classes. Acting, like anything else, is a craft and as such, must be studied. Many actors study their entire lives.
Joe's Acting class may not be where you want to study however. Research and find the classes or studies that professionals have used.

In much the same way that you would not enroll in Mary's Nursing classes and be accepted as a professional, you will find the same holds true for acting.

Have a good headshot done and take it with you to auditions and other appointments. Make it a professional shot that shows you in your best light.

You're also going to require a resume.
While at first it won't be as impressive as you might like, it will be something to show your versatility. As your work grows in nature and skill level, replace the lesser professional parts of your resume with other things are more impressive.

Use the head shot to send to all the casting directors and agents in your area, along with a resume, which you update, and resend about every six months, so that they are kept aware of what you're doing and changes in your current acting jobs.

Read publications of your trade.
In any profession, there are certain papers or magazines that keep you apprised of the trade, and keeping your nose to the news is always a good idea.
The Ross Reports, Variety, as well as some online publications such as newenglandfilm.com will keep you in the know about what is being cast, where its being cast and what they are looking for.

Make friends in the industry and never turn down an invitation to an industry event or party.
It really is not just what you know, but who you know.