[simpits-tech] Resistor for LEDs?

[Mike Williams]

Going to be using a PC power supply for my LEDs for my pit, using the 5v
line, what
resistor would I use to bring the voltage and amps down to 3.2v, second part
of the question, if I feed a terminal strip with the 5v line to feed all the
lines to the LEDs, (panel backlighting) could I use just one on the incoming
5v line, or would I use them on all lines from the terminal strip to each
LED, sorry if this question is simple, I'm just not much of an electronics
guy.
Thanks