How to art, a wordful description. I'm not a professional but this being my sixth year of drawing, I can give some tips.
Its simple, but effective. Drawing to start out is probably the easiest, and the supplies can basically be any pen or pencil, and paper. Accessible and you can do many things with it. Doodle away!
2) Keep a sketchbook or Notepad.
Throughout the day you may get some inspiration! Write about it, or doodle it. It may not be fantastic, but if you doodle the gist, you maybe can do a final of it another time.
3) Find your medium(s)
Mediums are what you are using. Pencil and paper, canvas and paints, wires and clay, markers and colored pencils, etc. Find what you like, and experiment. You may enjoy multiple!
4) Watch the artists do their thing.
Pssssst. Youtube is a thing! Go watch tutorials! That's what they're there for! You don't even have to draw/paint (or whatever they are doing) what they are making. Watch just for the sake of observing. Look at their techniques and process. Or actually do it too, it may help with your style, or artistic knowledge!
5) Observe the world around you.
We have lives, we live on a such beautiful world. Look at small details, like texturing of a fabric, or the bubbles in a soda. The bricks on a building. Appreciate it all, and just get a sense of the world, the textures, colors, vibrance. I personally think this will enhance your work.
6) Find role models, artists to look up to.
I have my own role models on dA. Look for some yourself! You may be surprised at who you find! Look for people who inspire you. People whose work you enjoy. WARNING: Enjoy the work. Don't copy.
I started out copying anime photos on google. (I don't know if I suggest this, copyright applies, and I didn't know about it then.) After some time, I kind of understood how I did it, and I tried freehand.
Doing it on my own, probably was the hardest, most frustrating parts of my drawing journey yet. I am still learning quite a bit, but that was rough. Keep going at it and you will improve!
8) Don't just practice. PRACTICE OFTEN.
Try to shoot for more then four times a week. The least maybe twice. Improvement will be much more evident.
And don't just do what your comfortable doing all the time. Do what you hate. Like HANDS. DRAW HANDS. They will suck for a long time, but you will pick things up eventually.
9) Don't . Give. Up.
That kid in your art class may be prodigy. That dude online may have sick skills, but you aren't them, and accept that. You are you, and you are LEARNING. Some people will learn quicker then others, and don't beat yourself up too much about it. If you love to draw, draw. Compare yourself constructively, not negatively. Your work is going to build on one another. You will get better. Eventually you will get your own understanding and style, embrace it.
10) DO WHAT YOU LIKE TO DO, NOT WHAT OTHERS TELL YOU WHAT TO DO.
If you hate doing landscapes, and have no interests in doing them, do what you enjoy. Don't do something you hate for the sake of someone else who can't appreciate how totally rad what you are doing now is. Its okay if people suggest to you to try something new. But them shoving down your throat you have to do something else is a no. Stand up for yourself.
11) Good luck and have fun.