Every default plan has 3000 API calls per entity per hour.
The rate limit kicks in after the first request has been made. The rate limit will be set to 0 when an hour has passed. Until the hour is finished, you will not be able to request data from the entity for which you surpassed the rate limit.
For example: If you make the first of your requests at 18:18 UTC it will be reset at 19:18.
When you make a request, the API response includes a header called
'x-ratelimit-remaining', this marks your remaining number of requests for that hour.