I am travelling to Hong Kong just for a short visit Friday - Sunday

To see a show in the HK Convention and Exhibition Centre and will stay near the centre.
How do i get from Futian to Wan Chai please and how much will it cost about?
I am assuming the best way will be metro/subway
will i be best buying a octopus card or single tickets or tourist tickets i will also need to return to Futian on the Sunday
Thank you for your help