Selection of some components

I am new to this website and I don't know if it is the right place or section.  I will try again in "General" this time.

If it is not right could someone relocate it to the right place.  Thanks.

I am also new to electronic so my requests might sound strange to some of you.

Night light project. (My first project.)

I need some help to select some components.

I have a 240 VAC/50 Hz voltage supplying a Bridge Rectifier (4x1N4007) with an output of 24VDC for 6 blue LED in series.

I have to step down the voltage from 240VAC to 24VDC.  I don’t know how drop the voltage from 240VAC to 24VAC.  It is where I need some help.

From what I read, to step down the voltage, I need a Cx capacitor (?? µf 400V) and one resistor R1 (??Ω) in parallel  to discharge the capacitor and another R2  (??Ω) resistor on the other side.

I know the Bridge Rectifiers change the current from AC to DC and I will need another C1 capacitor to smooth the ripples and a resistor of R3 (120 Ω) before my 6 LED.

I could use the values already available on different websites but I would like know the step by step for selecting the Cx Capacitor and the 2 resistors before the Bridge Rectifier.

Thank you.