Tap on the friend button located in the lower-left corner of the farm screen.

You can visit farms of other Farmers from either the Likes tab or Explore tab.

The Explore tab is where you can find random Farmers that you can add as Neighbors. You can also use the Search option on the left side to find a particular friend or Farmer using either their farm name or Player Tag.

Use the refresh button on the upper-right corner to generate a new selection of random Farmers.

Next, choose a Farmer from the selection then tap on the Visit Farm button.

You can collect visiting rewards from any Farmers which is capped to 5 daily.

To return to your farm, tap on the Home button in the bottom left corner at any time.