I've heard rumors/suggestions that you shouldn't worry too much about things until you have a clear revenue or expense plan that reaches the IRS minimums: https://www.irs.gov/individuals/check-if-you-need-to-file-a-...
ie: if you're making $100/mo (talk to your tax advisor), but if you're clearly making $3k+/mo then you should have a plan to incorporate, file taxes, etc. (and should also be talking to your tax advisor).
It helps to cool my jets when my brain gets into "unicorn mode" ... do I have 30 people RIGHT NOW who will pay me $100/mo? Am I supporting 3 customers who are each paying me $1000/mo? Are 300 people beating down my door to pay me $10/mo?
...probably not... and if they were? Then you've got the beginnings of a company and should start with the paperwork!