Power supply and dimmer/pot specs needed for LED A19 bulb in DIY desk lamp
an a19 has an e26 base, so its designed to operate on line voltage.  so you need to have a dimmable led bulb with an e26 base.  dimming will have to be done with a proper ul listed dimmer switch in an appropriate metal device box.  you cannot use a potentiometer for this.  you do not need a power supply if the bulb is designed for line voltage.  you can find hundred of videos on this sort of stuff on youtube or you can try www.make.com