Godot prototype

I want a start of a game engine for an idle game. I'm not looking for anything with much graphics, just mainly the focus on numbers/progress/gameplay. Examples Synergism/Increlution/NGU. I would like a prototype/basic game that I can then build on and add further systems/details as I build on it. The starting situation would be a blacksmith/crafter in a town and making different items for the people. The smith should be able to gain experience and craft faster/better. Further systems I would like to expand on is simulating the town with different events going on and quests from various people.