Hi I'm new to FunC. I am trying to figure out how to properly generate a payload to interact with smart contracts. Is there any tutorial, example or documents you would recommend?

I think you should see old TON Smart Challenges, to get familiar with cell concepts. The tests for TSC1 and TSC2 are provided, which allows to see how the payload is formed.
Also, you could examine code of any dApps while also looking at contract code and docs.

https://ton.tools/tutorials