Moving to Nairobi

Hello everyone, I am planning to move to Nairobi and hoping someone can let me know a few things. To visit for 3 months on a tourist visa, do I need to organise a visa before I travel?

Will i need to have return flight before I travel?

Has anyone moved from Australia to be married in Nairobi? If so how did you go about it?

Look forward to meeting a few of you.

Thanks.