This may help too:
"Coconuts can be found in the wild growing on trees. You can harvest and replant them at home in your own garden as well, but since it was only my second day on Sulani, there were no mature coconut trees to harvest from. That wasn’t an issue, though. The beach supply vending machine located on the main strip in Ohan’ali Town had fresh coconuts and pineapples for sale, as well as many other beach objects for some fun on the sand and in the water."
It's a quote from this Sims Community page:
https://simscommunity.info/2019/06/20/the-sims-4-getting-started-with-island-living/
I usually buy my coconuts from the vendor too, like @crocobaura mentioned. :smile: