Yes, if you are on a client machine, you will need to have Net8 installed.
As for the user name, password, and connect string, your DBA should be able to help you with that.
In order for the connect string to work, you will have to configure the Net8 installation on your client machine. Use Net8 Assistant to do this - it will prompt you for the information that your DBA will give you, then format and write this information to your TNSNAMES.ORA file. After this is completed, you should be able to connect to the database.