Photography courses/ activities (Milan)

Hi everyone, i am an architect/photographer visiting Milan for one month but i might be extending my visit to three months. So i thought I would practice what I do best which is teaching photography for beginners or mid level photographers or make discounted photo sessions for families, children or new borns as it is my speciality back home.
My question/ worries concern about any legal/ tax problems I might put my self in as I have a tourist visa type. Also if such small income activities like those are ok to be done casually, what would be the best way to advertise them or spread the word about them?
If I make discounted offers for internations members, would that violate the blog rules and be considered advertisement?
Sorry for the long post and I appreciate your support.