Need some help on the startup

I'm in need of some help I don't exactly have all the knowledge I need to get into the business and would like some feedback from other entrepreneurs or indie video game developers. I want to start my own indie video game company, however the issue is that I'm not sure what all forms I would need to fill out. Basically the steps of it all. Do I start with trademarking the name either through a lawyer or a site like legal zoom? Then off to the IRS to get a EIN? Do I then need to go to the county office to get a business licence? any help would be greatly appreciated.

Notes:

currently living in United States

have taken small business administration courses at college for now,

business will be entirely online