Command prompt to SQL and port number change

Go to Run  -> Enter cmd-> go to C disk i.e c:\ ->c:\> sqlplus /nolog -> Click Enter

You'll see SQL>

Hence You can connect SQL as:

conn system
password: ******

You can execute your queries.

You can change port using below:

SQL> Exec DBMS_XDB.SETHTTPPORT(3010);

PL/SQL procedure successfully completed.