For the initial enrichment of a database, most of our customers opt to do this enrichment offline due to Marketing Automation API call limits. One thing to note is that the Leadspace 'out of the box' APIs are architected to do enrichments through Marketing Automation rather than CRM, apart from one-off enrichments through the Leadspace Panel.
Note: Leadspace does also have a REST API that can be integrated into Salesforce; if you have the development capabilities to integrate and would like to discuss our REST API please contact your customer success manager.
In order to enrich your database, please see this article on what fields we will require in the export.
Once the file is received, Leadspace will enrich the data and have returned within 5-7 business days. Please find here a guide on what all of the appended data fields are.