I'm dumb, how to I expand a farm or add more crates to a warehouse

I'm running through the tutorial right now but there's some things I can't figure out.

I needed to add some crates to a warehouse I created but I couldn't find a button or option anywhere to build more crates inside an existing warehouse. I ended up just making a second warehouse.

I built a farm, tutorial said it needs to be big enough for 5 workers but it ended up only being big enough for 4. I click the farm but couldn't find an option to expand the existing farm. Ended up just making a second smaller farm.

Am I missing these options or do they not exist? It's hard to tell with the game's UI.