Buonasera,
The task was to turn one apartment into two which can be rented to tourists.
I propose two separate apartments, similar in size, but with additional common laundry/storage space which can be locked and have a washer/dryer for guests to use (for free or for a fee). It can also be used to store additional linens, cleaning supplies, even guest luggage.
Each of the two apartments consists of open space entry/kitchen/dining/living room, a separate bedroom and bathroom.
Both kitchens are small but they can accommodate sink, small under counter fridge, stovetop, microwave and even a dishwasher if needed. In the dining room you can either purchase classic dining room table or make a custom bar table. The sofa in the living room can be converted into a second bed so that the apartment can comfortably sleep four people. Bathrooms are both generous in size, but not too big, and they accommodate the shower, toilet, bidet and sink. Both bedrooms have a closet and a desk. Closet can be designed as an open closet without doors or classic closed closet.
I hope that you will like my design :)