Need a bit information please :) (Miami)

Hello everyone, beginning of September I am moving for 3 months to Miami. Joining a course in Miami Dade College, but I am looking for a way how to find a reasonable price studio in South Beach all I see on the net is just holiday listings or I have to use agencies . Is there anyway I can find and contact privately a landlord/lady that would like to rent studio/1 bedroom flat in SOBE? And as well I am looking for a sponsorship visa that will allow me to stay longer even after my course finish. I am having 10 years experience in hospitality industry with MBA International Business Project Management and fluent in few languages. Can someone please help me? Thank you !