Hi! Thank you for playing... and the very valuable feedback. Yes, we could surely have a better way of telling the buildings. A tutorial (if only we had more time) would have helped surely.
As for people, you build more houses, each house gives you 3 new people. Then you click on barracks, windmills or lumberyards and click the + or - buttons to adjust the worker numbers.
Thanks for the feedback, will have better explanations in future update.