There are tree relevant gatways for u. 1st www.stj.jus.br/ - the special court on Brasil. 2nd - www.stf.jus.br/ the supreme court on Brazil (and special court befor 1988); 3rd - https://www.jusbrasil.com.br/home a private gateway where u can research every courts.
You must pay atention to "súmulas" and "súmulas vinculantes" in STJ and STF courts (they r two special categories of jurisprudence, very important to brazilian judicial sistem) .