Honestly, for a brand new account, I always kick off with Maximise Clicks.
You need to establish a baseline. If the tracking is untested-and it usually is on fresh accounts-pushing for conversions straight away can be a disaster. You end up optimising for garbage data.
First job: let the system run a bit, gather clean search terms, and make sure your conversion tracking is actually firing properly. Once I've got maybe 20-30 genuine enquiries coming through, then I switch to Maximise Conversions.
And I never set a target CPA too early. That just throttles delivery before you've got enough conversion volume for smart bidding to work its magic.
Seen too many people screw this up by jumping straight into Target CPA on day one with zero historical data. Recipe for wasted budget.