So the first day ended with some rough sketches and a first prototype of the level generator. Basically it creates a level with rooms (8) connected by roads (9), by the parameters I give, like min/max sizes and number of rooms, general level min/max size etc. It's not the best algorithm and my first attempt at level generation, but it looks good at this stage.
I spent almost the whole day and night on this algorithm, making it acceptable for using, and started thinking about tile generating.