Self employed (DBA) and employed (Hourly employee) tax help

Hello! 
I am a freelance graphic designer as well as a hourly employee in the food industry. Before I file for my DBA as a sole proprietor, need some help. Researching for hours gave me a few different answers so I want to make sure I understand everything. Apologies for the clueless questions. Completely new to this. 

1. Do I pay annual taxes since it’s a DBA /sole proprietorship? Rather than quarterly taxes?

2. Getting a little bit of conflicting numbers, even after completing the ITA on the IRS website. I do not have to file taxes if the income from the graphics are below $499?

2. What documents During filing will I need since I’ll be an hourly employee as well as the Graphic design DBA? Obviously the graphic work won’t be a  steady regular income. I read that I will need to just attach schedule C 1040 to my personal taxes. Please guide me on this.

 

thanks in advance