I'm 17 years old and as a tenth grade student I took a painting class and loved it I'm now trying to start my own painting business from out of my house just doing paintings for people and I'm wondering what all would I have to do to get it started? Any answers are very much appreciated

What sort of paintings will you do?

An artist friend made money painting homes from a good color photograph. The homeowner then got the canvas framed and hung it in the living room or hallway.

Do you have a blog or web site? Or do you want to keep your customers local?

Perhaps advertising on criagslist or some other.
Talk to friends, family and get the word out. Talk to customers and ask them if they know others.

Basically paintings that people can use to hang in their houses I have done things based on a theme for class projects I love painting I just want to do it for others and make money doing it I don't have a blog nor website but looking forward to making one really soon and idc about the customer as long as I get them

House portraits are good, as suggested.
So are pets.
I would join deviantart.com, and I would list a few on eBay for free, but you will need a Paypal account.
You need a good camera and the ability to take good pictures or your paintings - very important.

When I was 13 I did ink and water colors of animals and sold them for not much at a local art fair, and it was fun. I had a walrus with a teacup, 2 penguins with tophats, etc - sort of whimsical stuff.