Claim and verify your profile
Your Google Business Profile is the single biggest lever in local search, it accounts for roughly a third of what decides the map pack. And none of it counts until the profile is claimed and verified. An unverified profile can't rank, can't be edited, and can't defend itself.
Claim it, then prove it's yours
Search your business name on Google. If a profile already exists, click 'Claim this business', if not, create one at google.com/business. Then Google makes you verify, usually by video (a short clip of your premises, signage and equipment), sometimes by postcard, phone or email. Video is now the most common, so have your storefront and a utility bill ready.
The traps that catch people out
Two things go wrong more than anything else. First, a duplicate: an old or auto-generated listing for the same business, which splits your reviews and confuses Google. Find it, and request a merge. Second, someone else claimed your profile, a past agency, a former employee, or worse a competitor. You can request access, and if they don't respond in a few days Google lets you take it over.
Search your exact business name in an incognito window. Confirm there's one profile, it's claimed by you, and it shows the verified checkmark. If there are duplicates, start the merge now.