Start with testing the pump by by-passing the existing wiring, just to see if it pumps. If not, you probably fried it. If the pump runs but still doesn't have any pressure start inspecting your hoses and hard lines. Do your tanks have any rust or debris in them, that could be plugging things up?
Necessary fuel pressure will be determined by what carb you are running.
Edelbrock/Carter AFB don't like much more than 6psi
Holleys will take up to 7-8psi without problems
Q-jet is about the same as the Holley
I'd recommend getting a quality electric pump with a regulator and adjust as needed.