Hotel
Clare and Matt are staying at the Hilton St. Louis Downtown at the Arch (https://www.hilton.com/en/hotels/stlddhf-hilton-st-louis-downtown-at-the-arch/). However, there are plenty of options in downtown St. Louis if you wish to stay closer to the venue or further out if you wish to be near attractions like Forest Park.
Train
Make use of the Metrolink trains to get around town or to the airport!
Flight
This is the closest airport to fly into.