Join the Facebook Community
Insurance
Business Bank Account or at least a 100% separate bank account. I recommend 2 accounts.
Income
Taxes - keep this account at a separate bank where you will not be tempted to spend it
Open Paypal and Stripe. While you may not need both, people may ask if you will take whichever you aren't using so it's helpful to have.
Becoming a LLC
I found this was actually very easy to do. Check out your states processes. Many companies over charge greatly.