It's better to start learning the ESP8266 by getting yourself a stand alone ESP development board first (they cost less than €5/$5, see my signature below).
After you're comfortable with the ESP, you can always experiment with other setups.
So you'll only need a ESP8266 board, a keypad and a relay (for the solenoid): I think the best bet to start off with is a Wemos D1 board and a Wemos relay shield.
For a keypad, you can use the pad as in your picture, but you can also attach a TFT-display with touch screen and make it all a bit more fancy (I'm working on a touch screen door entry system at the moment).
QuickFix wrote:There's no direct need to use an Arduino UNO: the ESP8266 itself can be programmed with Arduino if you install the ESP8266 core into the Arduino IDE.
It's better to start learning the ESP8266 by getting yourself a stand alone ESP development board first (they cost less than €5/$5, see my signature below).
After you're comfortable with the ESP, you can always experiment with other setups.
So you'll only need a ESP8266 board, a keypad and a relay (for the solenoid): I think the best bet to start off with is a Wemos D1 board and a Wemos relay shield.
For a keypad, you can use the pad as in your picture, but you can also attach a TFT-display with touch screen and make it all a bit more fancy (I'm working on a touch screen door entry system at the moment).
So Arduino is out of the picture for this idea