Hello Julie L,
CPA works good if you've received alot of data in your account and youve optimized it. Here is a great support article that helps understanding CPA: https://support.google.com/adwords/answer/2472713?hl=en
And here is a link to a post on this very forum outlining CPA vs. CPC: https://www.en.adwords-community.com/t5/Measure-results/CPA-Vs-CPC/td-p/5056
Hope this helps!
Welcome to the community¬
Based on the goal to be accomplished from the adwords, you can go for the strategy.
CPA is ideal when you have defined goals such as completion of sale, inquiry, lead.
If visibility is important then, you can go for display advertisements on search and display networks.
Two goals could be-
Branding: Increasing the visibility- CPM models on Google Display Networks using relevant keywords, contextual targeting, placement, audience targeting).
Direct Response: CPA model.
To implement CPA, you need to have atleast 15 conversions in last 30 days.
This is just a brief, if you need more details help, please elaborate.