i cannot find a hint on 'Oracle SQL Developer' and 'Oracle Database 12c' inside Linux shell

Question

I want to run 'Oracle Database 12c' for training purposes, but as i've installed 'Oracle OTN Developer Day'(Linux 6 works) i cannot find a hint on 'Oracle SQL Developer' and 'Oracle Database 12c' inside this Linux shell? In docs on ' Oracle OTN Developer Day ' i find its contents:

• Oracle Linux 6.5
• Oracle Database 12c Release 1 Enterprise Edition
• Oracle XML DB
• Oracle SQL Developer
• Oracle SQL Developer Data Modeler
• Oracle Application Express
• Hands-On-Labs (accessed via the Toolbar Menu in Firefox)

Where (what folder) to seek for them? Should i manually install 'Oracle Database 12c' and 'Oracle SQL Developer' above it? How to make db run and have SQL Developer connected to it?

UPDATE

picture of initial window in Linux: (no Sql Developer there):

Answer 1

You're logged in as root. You should login as user oracle instead.