Best Way to Structure API Access for an Educational Information Portal?

I'm working with an educational information website, Mi Portal FONE, that publishes guidance for teachers about payroll records, payment receipts, and related administrative processes in Mexico.

As the amount of structured information grows, I'm exploring whether an API would be useful for organizing and retrieving this type of data across different sections of the site.

For a relatively small information platform, would you recommend starting with a simple REST API, or is it better to keep the content database-driven until there is a clear need for external API access?