Hello, again… as per the forum policies… Searching this forum for keywords like Arduino, UNO, ESP as shield, AT, firmware, and so on would answer your questions 
The ESP with AT firmware is just a simple Serial to WiFi adapter… you program the Arduino and it communicates over that “shield” to the Blynk server.
Keep searching/reading for further details 
http://help.blynk.cc/how-to-connect-different-hardware-with-blynk/arduino/esp8266-with-at-firmware