How to implement Adobe Launch/Reactor API

Hi Priyanka, 

Implementing Adobe Launch (Tool) and Reactor API (API for Launch) are actually two different approaches to tackle analytics implementation needs, and in all fairness, for beginners, directly jumping on to API is not suggested unless there is any specific use case which is not being solved by the tool itself. 

I suggest start with this tutorial and later on touch APIs. 
https://experienceleague.adobe.com/docs/platform-learn/data-collection/tags/create-a-property.html?lang=en

I found this: https://experienceleague.adobe.com/docs/experience-platform/tags/api/getting-started.html?lang=en

and https://developer.adobelaunch.com/api/#

and also https://www.youtube.com/watch?v=dOCUdBmRw-c

I hope that helps.