Best insurance plans for preventative care

Going to start a new job in a couple of months that doesn’t offer health insurance in Georgia (Atlanta area)

High income earner so I don’t qualify for any kind of subsidy through the market place.

My understanding is that the marketplace offers private insurance plans. I’m also clueless when it comes to preventative care for any and all plans. I know for the most part that preventative care should be free. Don’t know if the laws have changed since I last looked into it. So, my questions are the following:

Is it better to get health insurance through the marketplace versus reaching out to the health insurance companies and getting insurance through them?

Is preventative care (shots, blood test, cancer screenings) free no matter what type of plan you get through the market place or through the health insurance companies?

Would the market place people be able to inform me of in-network coverage (hospital or doctor location) or would I need to go through the health insurance company to determine where in-network coverage is available.

Even if the coverage is out of network, is preventative care still free?