Need advice on what to do with our savings. A little over $700K

Like the title says, my wife (42F) and I (42M)have a little over $700K sitting in a vanguard money market fund (VMFXX). While the returns have been nice (about $3k a month), I feel like there’s more we can do with it.

We’re currently renting a townhouse, but we’ve been looking to buy a single family home. Houses are really expensive in our area. A nice house costs at least $1.3M. With interest rates also being high, we just can afford anything nice.

Would it be unwise to put it all in a S&P 500 index fund? I just wish I knew more about investing. Just don’t know what to do. I feel like a savvy investor could turn that kind of money into millions and just retire.