If you go to St. Louis, don't miss Busch Gardens.
And if you want to get a bit of history almost no one except Wash U grads seemingly knows about, check out the "east quad" of Washington University (immediately to the west of Forest Park).
Forest Park was home to the 1904 World's Fair, and the east quad (now Brookings Hall, Cupples Hall, and I forget the other two) was built for the Fair. It's what colleges ought to look like.
(Unfortunately, its not what colleges ought to cost: tuition alone has passed 40,000/year, though being a pretty rich university (it's t-shirts call Harvard the "Wash U of the East") that doesn't live and die by tuition revenues, this gets discounted a fair amount.)
I have a soft spot for Wash U -- I almost went to college, and did go to law school there (even with zero financial aid, I paid well less for the full three years than the estimated annual cost of $63K!). But I couldnt go there now.
There also used to be a fabulous pizza place right across the street from that same corner of Forest Park called Talayna's and a high-end restaurant farther west on Lindbergh called, I kid you not, "Wade's: A Gathering Place". Wade's is gone now, and so is the original Talayna's alas. I believe there's several of them scattered about the city -- original was known for bad service, great pizza (especially thin crust, before thin crust became a foodie thing). Was also place where I discovered fettucine alfredo.
One of most famous family-type restaurants is a place called "Mama's." It's on "The Hill" (may even be called "Mama's on the Hill", I can't remember) -- which is this old Italian neighborhood. Supposedly the birth of "toasted ravioli".
And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.
Romans 12:2 (NKJV)