Due to Construction works on the S-Bahn tracks south of Stuttgart Central Station, there is currently no direct line from Stuttgart Airport to Waiblingen.
You can use the U6 from Flughafen/Messe to Hauptbahnhof (Arnulf-Klett-Platz) and then rejoin the S-Bahn Lines S2/S3 at Hauptbahnhof (overground) to continue to Waiblingen.
You only need one ticket for both trains, they depart every 30 min. Also, important for the Central Station: you will have a 5-10 min walk between the two parts of the Central Station as the Mega project “Stuttgart 21“ is still on going.
In Waiblingen you can use the local Bus lines 204, 207 and 209 to get from Waiblingen Bahnhof to Bürgerzentrum (Hallenbad). Or you take a short walk of 20 min to the Venue. This only takes 5-10 min by Bicycle.
Fore more info you can use the Website of the VVS (Verkehrs- und Tarifverbund Stuttgart)