What kind of help do you need? Where are you having difficulties? Have you read the OTA documentation that comes with the product? The documentation provides lots of examples of how to establish a connection and extract data for a variety of entities.
You may need to look also at the Site Admin API. Without additional investigation, I can't guarantee that the OTA API would support you extracting all the info you're looking for.
Both APIs require you to establish a connection with valid QC credentials, and that user must have adequate privileges to access the info you are trying to extract.
(Opinions and information contained in this post are wholly my own and do not reflect the opinions of my employer.)