Capacitor questions

General
1

Hello, I’m going to attempt to make a prototype that works like a camera flash (capacitor briefly powers led). I have never done anything with capacitors before so I’m going to start small to avoid accidental death by electricity or whatever.

The led is going to be 2,8-3,6V 20 mA and the capacitor will be scavenged from an old circuitry board.

So how would I charge the capacitor? And how would I limit the capacitors discharge enough to not burn the led?

Here’s some of the capacitors I have available: 10V 220uF, 16V 100uF, 16v 220uF, 6,3V 220uF, 25V 47uF, 50V 4.7uF.

I also have a bunch of 1/4W resistors.

2

Let’s say I try charging a 50v capacitor with two AAA battery’s (3V). Would it charge? And will the capacitor release/discharge/supply 50V or 3V?