Honestly, the two best things you can hire once you have some minimal traction are the best lawyer you can afford and the best accountant / business manager you can afford. The third bit of advice is just something you should tattoo inside your eyelids: cash is king.
Now, on with the first two.
"Hiring the best you can afford" doesn't mean hiring the best brand (Skadden. PwC etc). Find the person with the best technical expertise relevant to what you're pursuing. They're often stars from those shops who've gone out on their own -- just like you did.
Why? Don't you want to spend your money on a star engineer or great marketing?
No. Because you're in this game to win. And winning these days (whether going for an exit or, you know, an actual profitable business) needs you to have at least the following:
(1) Not make (or, more likely, not know how to avoid) stupid mistakes or ill-advised moves legally.
(2) Not screw up the administration of your business
Even if you do everything else right, errors in either 1 or 2 can prove fatal. Like, literally, you will lose everything.
Good lawyers are like good soldiers these days. You don't go to war without soldiers. And you don't do modern business without the best legal help you can get. Even in the most advantageous, optimistic, friendly scenario, run it by an attorney who knows their stuff. First. During. Last. Or wander onto the battlefield with people who outgun you. You've been warned.
Next: good business administrators are worth their weight in gold. It is a distinct skill and some people really are called to love and be good at book-keeping, accounting, cash flows etc. Do not screw yourself on taxes, audits, book-keeping, invoices slipping through cracks, agreements not being fulfilled or anything in the "admin of business" that keeps you from staying laser focused on you do well -- which is not business admin.
Finally -- remember, business is business. Repeat it to yourself early and often. Business is business. The VC who seemed really friendly and just "gets you"? Business is business. That particular contract term that just doesn't sit right with you -- but the person on the other side keeps telling you not to worry about it? Business is business. Your cofounder is your best friend but now they're not pulling their quota? Business is business. This isn't being machiavellian. It's that everyone will be applying it to you.
Ultimately, good lawyers and good business administrators will ensure that you remember "business is business". Don't leave things to chance. Don't trust. Don't be emotional . Business is business and if you're not controlling your agenda, someone will be controlling it for you.
There's enough sh*t in business you can't control. At least stay in control of what you can.