Follow these simple guidelines:
1. first, call yourself an artist,
2. practice,
3. mess up a lot of paper, wood or canvas,
4. get better at it.
Like many things, becoming an artist is simple, but not always easy. But it can be VERY fun.
It's important to experiment with different supplies and find out what you like and what you don't. I love acrylic ink, watercolor, charcoal and acrylic paint. These are fun to use and you can easily make corrections. I hate wire; it scratches, pokes, kinks and breaks. But you may find that you love wire and hate ink and paint! This is what makes art so interesting and wonderfully diverse.
Through experimenting you may also learn if you're Goo Positive or Goo Negative. This is very important. If you love to get covered in clay, sand, glue or paint, you're probably Goo Positive. If the thought of immersing your arms up to your elbows in paper mache paste makes you want to gag, you're probably Goo Negative. Choose your art medium accordingly. Never be afraid to experiment, but respect your gut feelings!
Visit your library and check out books about art, everything from yarn bombing and fiber art, steam punk, graffiti, cartooning, painting, scrapbooking, sculpting, cake decorating, book binding, papermaking, drawing, caligraphy, folk art, earth art, junk art, performance art, photography, woodworking and video. It will enrich your soul, open your mind, sharpen your eye, enhance your skills, and boggle your mind. You don't have to read it all, just enjoy it, soak it up, file it away.
Look for supplies and ideas everywhere. Art can be made with found objects, sticks, rocks and leaves, or drawn on expensive computers using fancy software. It doesn't matter, it's about creating and practicing.
So get out there and make art. Make bad art. Then make somewhat better art. Then make great art!