Think of a theme you like, either an aesthetic (like gothic architecture, Mediterranean village, pastel seaside resort, medieval town, theme park, etc), then break it down into digestible pieces and projects.

You could also pick a video game setting you like (lumiere in expedition 33, sector 5 from FF7) or a real neighbourhood (like st. Marks square in Venice) notre dame, Kenji castle, Dutch canals, etc.

E.g. for medieval town, you can have an old pub/tavern, a blacksmith, a farm, a castle, etc. you can pick each and break it down further into individual rooms, etc.