Start, you will figure most things out along the way. If not, you can pay someone to help figure out what is beyond your skill/knowledge level.

Echoing a lot of comments in thread so far, it is a balancing act of focusing on generating revenue and limiting liability depending on your situation. Do not spend a significant amount of time setting up an LLC, as it will slow you down, hire a lawyer to help or a registered agent so you can focus on getting the business going.

edit: spelling