In the class Cardio Core, we use resistance loop bands during the class. These are a great fabric option by Meglio - the medium purple one will be perfect. They also stock slightly cheaper latex-free bands.
You should also be able to get resistance loop bands from Amazon, Argos, Decathlon or similar store.
A kettlebell is required for the class, Lift. An 6-8kg kettlebell is recommended to start with. If you'd prefer to loan a kettlebell from myself for the short-term, please let me know and I'll be happy to lend you one from the studio.