Steps to marrying a citizen, please

Hello,

I'm from the UK and wanting to marry my Namibian partner.

After doing research and sending emails to institutions with no response we are very unsure on what the steps are to get married.

I'm hoping someone can tell me what the exact steps are to getting married..

And

Would this mean I can legally stay in the country after the marriage at the magistrates court?

Would I also be able to to work?

Thankyou