The first possibility to create new database is using the DBCA.
1. Run the dbca
2. On the Welcome screen click next
2. On the Welcome screen click next
3. On the next scree choose Create a Database
4. Choose the database type you want to install. I have chosen the Custom Database
5.Set the Global Database Name and the SID of the new database
6. Check if you want to use the Enterprise manager ( Listener has to be configured)
7. Type the password for the SYS and SYSTEM user
8. Choose, where you want to place your datafiles
9. Choose if you want to use the FRA
10. Choose the components you want to install ( If you have clicked Custom database in step 4)
11. Click the Standard Database Components if you want specify the basic components
12. Review the instance parameters
13. You can modify the Tablespace, controlfiles and redo logs location and sizes
14. Choose if you want to create a database or only script, which can be started manually later and click Finish
After you click on finish button, the database will be created and can be normalyy used.