Why do you need to establish it as an LLC?
You need to understand your state’s tax laws, but in general LLC would be for separating you from any of your assets; otherwise, unless you are making upwards of like 70k in net business income per year, you may not need to file as a LLC.
As for licenses, check your state laws. Depending on your business, and it’s structure, you may be required to obtain necessary licenses. You may need to register your business with your state as well; again check your state laws.
In most cases, there’s really not a whole lot you need to do to establish your business. Most of the time it’s literally just saying “my business is launched!” Once you have any needed licenses, you’re set to start operating.
Honestly, Google is your best resource here; can find most of the answers to your questions by searching there.
Other things you may need to consider: -marketing and advertising -location of operation -overhead and startup costs -if you’re filing as LLC, what kind? How will you pay yourself? -keep track of ALL business transactions -do you need other employees?