Unknown port - Looking for a VGA converter
That looks like a white MacBook Core Duo 13-inch, and while I have not seen one of those for a while (congrats on keeping it running!) I believe that is what is called a mini-DVI port.

So a search for mini-DVI to VGA should find you the adapter you are looking for. I doulbt Apple still carries it and you might have to buy a used adapter (ebay and the like) but that is the spec.

BTW, in the future when asking for help on something it is best to give the model number, part number or official designation of the hardware (if applicable) and/or the version of macOS on the Mac, also if applicable. You are more likely to get an accurate response, and a faster one.