Hi Developer12, First:
Can you please read this page.
Second:
Check https://academy.uipath.com if there are any courses about your question. The CV Training and Update course will show you the basics and have some examples which you can download.
Third:
Check the UiPath docs section.
You can play with CV on a local server, or use the ApiKey from the cloud platform.
From there on, give it a try and see what questions you have after that.
That way it is easier for you to understand and for us to help/guide you.