>>52868282You don't need to go anywhere or even really play much of Pokemon GO to get Meltan, it's actually pretty easy to get it and trade it to the main games:
>connect your Pokemon GO to your Home account in the Go settings>send any random Pokemon into Home (don't forget to pick it up before sending a Meltan)>this will give you a "mysterious box">open it >Meltan will spawn around you for half an hour>catch one, go back to the settings menu and send it into Home>enjoy your MeltanIf you want to get a Melmetal as well, then catch as many Meltan as you can because you get candy for catching them and you need Meltan candy to evolve it (also use Pinap berries because that makes them drop more candy). This will take a bit of time but you can reopen the box every 3 days to make more Meltan appear, then once you have 400 candy you can evolve it before sending it to Home.
If you want a shiny one you'll have to wait because they only enable the chance for a shiny one to appear during certain events, such as the anniversary (which is in July). The shiny rate is something like 1/64 and they let you open the box more often during that time, so it's a fairly easy hunt.