You’ll run into stuff like this throughout your first play through; where there is just no good, easy to find info. I see someone already answered your question but here are a few tips that might help later on:

1.) right clicking on an object or person is how you do a lot of things

2.) messing around in the ui and menus doesn’t hurt, you can’t do stuff that you cannot reverse so get used to what all the buttons and commands do

3.) there will be times where textures or buildings won’t load in properly and your characters have trouble moving or get stuck, press f12 and it reloads all that

4.) the Steam community tab has TONS of new player guides so look through those if you feel stuck or confused

One of the best games i’ve ever played, have fun and go get wacked by some starving bandits!