Solo traveler(35M), What to in Joburg for Christmas and Cape Town for New Years?

I'm (35, Black American, Bisexual, man) traveling to SA at the end of December landing in Joburg and will be there for two weeks. I'm thinking of doing one week in Joburg (Christmas) and one week in Cape Town (New Years).

I've been to Joburg before but that was a decade ago. I've never been to Cape Town.

Any suggestions or recommendations?