1. Yes, you can integrate Online Maps and use it to display a map.
Online Maps is a mapping framework that you can easily adapt to your needs.

2. Yes, Online Maps supports GPS out of the box.

I saw this Asset in the Assetstore and I'm curious if this is the right Asset for me.

1.
My goal is to write a GPS game that works with a 3D Map with Geodata. It will also have lots of Scenes without any Maps. I want people to be able to build and do stuff on the Map view, some units need to be moved by the Player by GPS and some move on their own. There will be a lot of UI built. Can I integrate "Online Maps" and use it for Map Display?

Why am I asking? The description sounded to me not like the Asset is a Tool that I can use like a function in Unity but it sounded like it's a complete App.

2.
Is there GPS support included (Android, IOS, Win) or do I need a separate Asset for that?

Thank you in advance!