Powering my projects and breadboard
For low-current applications (less than 1A) you can use linear regulators to get the voltages you need. Just add one or more capacitors between + and - before and after them according to the datasheet of the regulator. The LM78XX/LM79XX line is the most popular for 5V and up, but there are others too. For 3V3 there are also many options, for instance the LM3940IT-3.3. Other voltages are equally easy to find, just search for "LDO" in a components distributor like DigiKey, Mouser, Farnell, etc. and filter for the current and voltage you need, and select the "through hole" mounting type since you're gonna use them in a breadboard.