Quote: "1) Are there any taxes I have to pay for selling the media?
2) Do I have to declare myself a company(or create one) in order to sell media?
"
Regarding digital media, I don't know. You should check your state tax webpage. For example, north dakota's is here:
http://www.nd.gov/tax/salesanduse/pubs/guide/index.html
You should check with your local SBA office, their website is here:
http://www.sba.gov/
They can answer both those questions for you.
I can answer number 2 though, you shouldn't need a license if you want to sell products under your own name (or with your name in the business name, like "John's Digital Media") as a sole proprietor. There are tax things you need to take care of. Running a business as a sole proprietor may not be best suited to you, so you should look at your other options. For example, starting up an LLP is only 25 bucks, and affords a lot more protection.
States may vary, so check your local state business info page.