It's an old tutorial and some information out of date
These steps total 6 transactions on the Ethereum blockchain. Be wary of gas prices before you start. Make sure you have enough ETH in your Wallet. Gas was at ~50 Gwei at time of doing this tutorial.
This will happen in two steps. An Approval and a Swap step. Both will charge gas!
The warning says exactly what it means. It's up to you to make sure the addresses you are using are correct. You might want to click on those View on Etherscan links and verify them against Harvest's Github page.
This will also require two transactions: Approve and Supply
This will also require two transactions: Approve and Stake
I went to Uniswap and don't see my posiitons!! When you add your UNI_LP tokens to Farm, you temporarily stake your LP tokens into Harvest, and Harvest use it to farm and sell crops to grow the amount of your LP. The value of your LP still grows with each trade on the Uniswap pool. So you get to enjoy Harvest's automated golden crops on top of Unicorn yields.