You can use Third Party Tools like Toad or Navicat which have excellent GUI to get you logged into Oracle
But if you want to go the traditional way; find below instructions
- Open Command Prompt
- Type: sqlplus sys/password@<hostname>/<global service name> as sysdba
- Typing the password in this manner is never recommended; instead use below option
- Type: sqlplus sys@”<hostname>/<global service name>” as sysdba
- It will then prompt to enter password
- An alternate way is to log into SQL initially without a user
- sqlplus / nolog
- Now under SQL Prompt; type connect sys@”<hostname>/<global service name>” as sysdba