If FortiCloud allows you to export logs, you could periodically download them for offline analysis. This would let you view more than 2000 records at your leisure. Try to increase the log retention settings. This could enable you to keep logs for a longer period, making it easier to review historical data. If you're looking for specific types of traffic or events, use filters to narrow down the logs you're viewing. This can make it easier to find what you're looking for without having to sift through thousands of records.
As previously mentioned you can refer these documents:
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.