Build in public day 27/30: I forgot to post last night, so this update is for yesterday and hopefully saves you a bunch of time researching incorporation/formation.
One of the best things we did early was incorporate with Stripe Atlas since it minimized what we had to change later. Atlas makes formation (DE LLC or C Corp), EIN, basic documents and templates, as well as getting a bank account and registered agent setup extremely easy. The templates were useful later and saved us a ton in legal expenses.
On top of that, Stripe Atlas includes a number of discounts for other services once you're setup. You can also get a discount on Atlas itself if you do YC's free online Startup School program, which also includes perks like $5K in AWS credits and others. It's $500 full price, but we paid only $250 with the discount from YC's free Startup School program (which I assume they still have).
The downside is that I wish you could incorporate in other states like WY or NV, but I get that they need to streamline it with one state.
One other thing I'd say is if your company is growing well and you have confidence in it long-term, then incorporate in your product's name (as C Corp if you plan to fundraise). But if you're uncertain, incorporate as a more generic 'holding company' name so you can pivot, launch different products, and experiment as much as you like without the hangover of an old product name.
C Corp or LLC? An LLC is much simpler to manage than a C Corp, which has more complex taxes, filing requirements, management, etc. and is only worth it if you need what a C Corp uniquely offers (e.g. better for fundraising or other situations you can ask your favorite LLM ).
Lastly, why use something standardized like Atlas, what if you want to do something different with your structure? Short answer: don't. Innovate on your product, tech, distribution, etc. but don't innovate on corporate structure or anything like that. Unless it's a core competency of your business, it's more trouble than it's worth and can create big issues long-term.
Relevant links:
Stripe Atlas: https://stripe.com/atlas
YC's free Startup School online course: https://www.startupschool.org/