If you want to proceed to a regular admission, if you are a non-EU* national and you do not reside in Italy (you don’t have a Permit of Stay in Italy) you must file a pre-enrollment application to the Italian Embassy or Consulate in your country as explained here.
(*) In this context, the following countries are considered to be part of the EU: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Norway, The Netherlands, Poland, Portugal , Romania, San Marino, Slovakia, Slovenia, Spain, Sweden, Switzerland, Vatican (Holy See), United Kingdom.
Then you can proceed to the application here.
For information about grants please check https://studyinitaly.esteri.it