How does paying a house with cash work?

Let say I win 1mil from a lottery. Find a nice house for 400k and want just pay the entire price at once, no mortgage or any loan.

What is the total cost that i need to pay? The 400k, the real state agent, and what else? Any tax? Fee? I see the "monthly ground rent" listed for some houses. What is that? Does it apply for every house? I just want to know the process and the costs of buying a house with cash.

No need the downside of it like liquidity or repairs or if some emergencies come up, since I still have the 600k left.

Then after I owned the house, what do I need to pay monthly? Electricity, water, trash service? Any other fee?

Thanks.
Added (1). I'm in Chantilly, VA.

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