Power 24V external component + blue pill, control external component
You are heading in the right direction; let’s suppose you get a 24V power supply with can supply enough current to the atomizers.

The most efficient is to use a Buck DC-DC converter module to transform the 24V -> 5V with an efficiency of about 90%. Alternatively you could use a linear regulator, but it will dissipate a lot of power depending on how much current you need at 5V.

To turn on the atomizer you could either use a relay (driven by a little transistor connected to the MCU) or a MOSFET rated to carry the current of the atomizers.

Edit: as mentioned by Vlad, the atomizers listed are just transducers. So they need to be driven at the correct frequency - not just a DC voltage. For this MOSFETs are more suitable than a relay.