You can access APIs as per your flexibilty using different options available.
Detailed information about options are available to each endpoint description.

Include
You can access more details about some entity by using include query param, you can also access nested entity information.

For Example:
For fixtures api you can pass include=round,tournament.court,tournament.country to access particular entity.

Filter
You can filter out results by many options available to particular entity. You can apply multiple filters with multiple values

For Example:
filter=PlayerGroup:both;TourCountry:USA,KAZ,ROU,GBR

Pagination
You can load data in chunks using pagination query params

For Example:
pageSize=100&pageNo=1