You do not need much to start building circuits, and most of it is cheap.
The short list
- A solderless breadboard and a pack of jumper wires.
- A 9 volt battery with a snap connector.
- An assortment of resistors. Values from 220 ohms to 100 kilohms cover most beginner circuits.
- A handful of LEDs in a few colours.
- A few ceramic and electrolytic capacitors.
- Two or three general-purpose transistors and a 555 timer chip.
- A basic digital multimeter.
What can wait
A soldering iron, an oscilloscope and a bench power supply are all useful later. None of them is needed to build and test circuits on a breadboard.
One habit worth starting on day one: disconnect the battery before you move a wire.