You can't start a new city. I city exists for all the things you can do. Your new city will have nothing to do because nobody lives there and there are no jobs to attract anyone to move.

that is why we build suburbs - they get anound this by being right next to a place with everything you want in a city

This is actually how you start a city though, you build a suburb and wait for it to grow into a city. This takes a really really long time so it's better to build near existing cities.

We don't observe this phenomenon occurring often in the modern day only because cities sprawl rapidly and so the evolution of the suburb becomes a borough of the existing city rather than a brand new city. Otherwise Brooklyn, Jersey City, Weehawken, etc. would all be considered new cities instead of being referred to as the NYC metro.

Sure you can. You just need enough land and money to start basic things like a post office, city hall, courthouse, roads, and a way to get power to the whole thing.

See Starbase, Texas

It obviously wouldn't be successful on day one, and it would take some kind of exceptional pressure to jump start it, but these things have been done in the past in the US and have been done recently in China. Not arguing these were good things, but they have happened before.

Think back to the old "company towns". Lowell, Massachusetts, built for a textile mill. Hershey Pennsylvania, built around a chocolate factory. Fordlandia, Brazil, a rubber plantation town. All of these were essentially cities and towns planned out around a central industry.

Similar things happened with the ghost cities in China with several of the big notable ones eventually actually growing into real, functional cities.

Once again, these have all kinds of messy histories and I'm not saying they're all good ideas. But just pointing out, it can be done.