Provide more info like os and its version - https://blogs.oracle.com/shay/entry/10_commandments_for_the_otn_fo
Did installation complete successfully?
check if database is up
start command prompt
sqlplus / as sysdba
select open_mode from v$database;
check the status of listener
Post the output of above commands here
do u have tomcat apache or glassfish installed in your system.even it may take the same port for their execution
if yes you have to reconfigure port no for either one of the application.
if no try in another browser to open it.
if then also problem arises.there must be problem in lsnrctl. for that post ur lsnrctl status as yoonus said