@Francisca16 I am so pleased that I could be of assistance. You have received excellent advise from @Julia66. Long term reservations are very different from short term. Help Center has some important information about long term including payments and cancellations. Also, cities often view rentals over 30 days under different regulations. So much to learn!! You are a great student so that is your best asset.
About describing common spaces, take pictures and with each picture provide a description about how the space is either private or shared. It helps guest understand the set up. Good luck with your new bookings!!