Immigrant from blynk

Hello my friends, I am an immigrant from the blynk platform. I would like to interact with cayenne. Is there an explanation of the basics of dealing with cayenne, I mean how do I read the values ​​from the application and send them to the application as well

you mean show data from blynk to cayenne? then it is not possible.
If from device to cayenne then have a look at the docs Cayenne Docs