I’d start by asking people around you if they know an attorney. Recommendations from people you know will almost always be more valuable than a Google search.

If you don’t know anyone that would be in the area of law that you’re looking for, ask for _any_ attorney recommendations, then ask those attorneys for recommendations for people in the area of law you need.

If you absolutely cannot find a lawyer through people you know (and, really, try asking people), then you can look up a lawyer referral service for your state. Most state or county bars will have some program for making referrals to lawyers. Often these will have a low-ish flat fee, which will get your a short initial consultation with a few lawyers in the relevant area of law.

For billing, it’s something to ask your lawyer, thought most lawyers will have some kind of billing program where you pay hourly for what you use, and don’t need to pay some ongoing fee just to have the lawyer as “your lawyer”. Small business that only need a lawyer for a few hours a couple times a year aren’t uncommon clients for business lawyers.