Planning benchmarks put U.S. search-ad conversion rates in the 4–7% range for most service categories (we use LocaliQ's published averages in our calculators). Well-matched local campaigns with tight landing pages regularly hit double digits; under 2% means the page, the tracking, or the traffic is broken.
Diagnose in that order: page first (does it match the ad and convert in 20 seconds on a phone?), tracking second (does a test submission count exactly once?), traffic third (are the search terms actually your buyers?).
And define 'conversion' honestly. A counted phone call and a counted pageview are different economies. Benchmarks only mean something when your conversion action means a raised hand.