Unable to connect to oracle database. Getting ORA12505 error
This: The listener supports no services.

Your database is not started, or it is registered into a different listener.

Assuming you have the simplest default configuration, just start your database with oracle user:

$ . oraenv
ORACLE_SID = [oracle] ? orcl
...
$ sqlplus / as sysdba
SQL&gt; startup


Do not forget case sensitivity when providing the value for ORACLE_SID.