Before we can offer you help, we need to make sure you understand Blynk and what it does.
You should read everything here first. http://community.blynk.cc/t/blynk-for-beginners/10000
Then you should read this about asking for help: http://community.blynk.cc/t/readme-welcome-to-blynk-community/10304/3
Please come back once you have tried the methods in the examples and have a good understanding of Blynk basics.
To read the sensors, forget about Bylnk. Its only going to confuse you.
You need to get the sensor working WITHOUT Blynk first. Monitor data via Serial. Once you have a working app, start to integrate Blynk.