Are there any spots for a picnic

Plenty

For the little more adventurous type picnic you can go on the River Bluff hike and have a really great view of the river. There are benches at certain locations but no picnic tables on the Bluffs

Pavilions and random tables throughout the park.

Oh yeah

Yes there is spots for a picnic they have table s and open spots

Lots of open picnic tables. Some with charcoal grills. There are a couple of large pavilions that can be reserved for functions as well. If you feel like hiking and don't have little ones to watch, have a picnic lunch up on the bluffs above the Meramec River. The view is the best one along the Meramec in stl that is open to the public.

Yes

Absolutely. Bring a blanket though, there aren't picnic tables from what I saw.

Yes, lots of picnic tables or open spaces to bring a blanket and sit on the ground for a picnic. So beautiful!!