Wireless switch using ESP8266
p.s.: From the level of your questions I assume you are starting with electronics, and I should say this is not recommended as a first project because mains voltages can kill or severely harm you either due to direct shock or fire, etc. Please consider doing a similar project controlling lower voltages first (12VDC for example).

1.NodeMCU will give you much more GPIO and is arguably easier to develop on due to the onboard USB to serial converter. It is also easier to plug into breadboards.

2.You can control 2 relays with 2 outputs from the same microcontroller (with the appropriate driving circuitry, unless you are using modules like this or similar, which already contain the driving circuitry). No need for one ESP for each relay.

3.You can probably use a 5V phone power supply ("charger"), provided it can supply enough current for all the relays you are using.







simulate this circuit &ndash; Schematic created using CircuitLab