In the Web version, arrow keys scroll. Click on any object/person to try to interact with them. Your view is always in "overhead god mode", so you do not need to control your character directly (For example, you can start to plant a crop then scroll up to the shop and sell off your last harvest--you do not need to 'walk' your character to the shop).
Edit to add: Your starting/main character ('Lori' in my game--I am not sure if the name is random or not) is at the bottom of the _longer_ stairs/steps. You do not need to manually move them: They will move automatically where they need to once you assign them a task/job.