School project? This type of "power supply" is absolutely not suitable for a school project.
Please do not use this so called "power supply" design. Although the voltage on the secondary is low, the whole circut is connected to mains and thus potentially lethal.
Throw away the power supply section and use a well insulated safe power supply, e.g. a USB wall wart. Or an adjustable wall wart for higher output voltage and power.