Getting my lo baptised and just wondering about the preparation class

Hi 1st time writing on anything like this but looking for advice really.

I have my 3rd sons baptism booked for 3rd of July and I have to go to 2 preparation classes with the godparents. 

I never had to do this with my other too (8 and 13 years ago) so I'm just wondering do I/godparents need to take anything and what happens at the preparation class. The lady on the phone of the church wasn't very helpful tbh and I can't seem to find any info online. 

Thanks in advance for your help