Need help choosing a power supply for a breadboard
You will want to invest in a "lab power supply" or "benchtop power supply" which is typically a single or dual channel adjustable supply, such as this one:

https://www.sra-solder.com/korad-ka3005d-precision-variable-adjustable-30v-5a-dc-linear-power-supply-digital-regulated-lab-grade

They come with cables that have a banana plug on one end and an alligator clip on the other. You can strip a short piece of wire to go between the hole in your breadboard and the alligator clip to provide power easily.

Bigger breadboards have binding posts which is a round connector you can use for power, that also accepts a banana plug. That way you can use a cable with banana plugs on both ends to conveniently route power from your power supply to the large bread board. Here's an example of one:

https://www.adafruit.com/product/443

For your application you may want to pick a power supply that can provide the maximum voltage you need (say 30V) and then add voltage regulators on the breadboard to provide lower voltages as needed, such as 5V or 12V that are derived from the 30V source.