Reddit mentions of ELEGOO Electronics Component Basic Starter Kit w/Precision Potentiometer, Buzzer, Capacitor Compatible with Arduino UNO, MEGA2560, Raspberry Pi

Those kits are OK, but I might suggest getting yourself some boards like these:

https://www.amazon.com/gp/aw/d/B00CGV6TZG

And a basic component kit such as this:

https://www.amazon.com/gp/aw/d/B01EROKLBC

With those you can practice all you want and come up with your own configurations. Start with getting an LED to light up and go from there.

For a cheap multimeter I like this one:

https://www.amazon.com/gp/aw/d/B000JQ4O2U

Take a generic NPN transistor like the 2n3904, 2n2222 or if you're in Europe, the BC547 or BC548.

Look up the datasheet of your transistor on Google and determine which pins are the Base, Collector and Emitter.

Hook up the collector to the negative pin of your buzzer. Then hook up the Emitter to the GND of your Wemos.

Now that you're left with only one pin on the transistor, the Base, hook that up to a resistor (somewhere in the 1k to 10k region) and attach the other side of the resistor to a GPIO on your Wemos. Oh and apply 5V to your positive pin on the buzzer. That'll do the job just fine!

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Edit: get yourself an electronics starter kit like this one:

https://www.amazon.com/ELEGOO-Electronics-Component-Potentiometer-Compatible/dp/B01EROKLBC/ref=sr_1_7?keywords=transistor&qid=1566454567&s=gateway&sr=8-7

Should have everything you'll need.