You don’t say what sort of ESP boards you’re using. If they are the ESP-01 boards (8 pins at one end of the small board) then I’d forget them and go for NodeMCU or Wemos D1 Mini boards instead.
The choice of GPIO pin you use is important, see this handy post:
Also, don’t forget that the numbers printed next to the pins on a NodeMCU or Wemos D1 Mini Board aren’t GPIO numbers, you need to refer to a pinout diagram for your board to translated the D numbers to GPIOs.
If you’re trying to manipulate your GPIO pins directly (by selecting Digital rather than Virtual pins in the Blynk app) then you have limited control over what they do.
I always use Virtual pins, and set them to the desired state (HIGH or LOW) immediately after startup with a digitalWrite command in the Void setup (don’t forget to issue a pinMode statement first for that pin, so that the code knows that it’s an input or output pin).
Pete.