have been thinking of taking up that hobby from time to time. somebody here with some insights into it? how would get started?
Best way to get started would be to watch The Detectorists on Amazon.
The Mojave nugget was found in California with a radio shack metal detector https://en.wikipedia.org/wiki/Mojave_Nugget
The hardest part is getting permissions from land owners, many of whom have no idea what you're trying to do and are therefore rightly suspicious. But I'm fairly outgoing and friendly in nature so that hasn't been too difficult.
As others have mentioned, if you're in the US, you're unlikely to find very old things like European and Asian hobbyists are able to, but finding 150 year old coins and war relics is satisfying enough for me.