Thank you for giving me the exact names of components, tomorrow I will try to find them locally.
About the breadboard, it's only used as I do my tests, sincerely I didn't expected to be so simple to dim my leds. This means I can remove the relay module and just use a simple 2 (resistor and MOSFET) or 3 (resistor, transistor, MOSFET) components on a PCB ?