ESP32

Buy an ACS 712 ammeter, the integrated board should not cost more than $3, and you don't need any special high voltage isolation, it comes with 10 A terminals. You'll get a decently accurate current reading, multiply by your socket voltage to get power in watts (120 or 220, which is actually 240 volts nowadays, you should know), but you need to read it like 300-400 times per second for AC. Just beware that even the manufacturer says the chip itself is rated for 30 A, your terminals will become melted plastic at around 15 A, and you won't even fit the wires rated for more than 15 A into them.

https://www.amazon.com/acs712/s?k=acs712