Hi Yoshi,
It looks like you've deleted all of the pre-set demo objects from Landshark, and are now adding your own custom objects?
If so, what I notice from your third screenshot is that, in the "Databases" panel of the "ls_dsources" environment, you have correctly added (or discovered) the "Dataset Home" (a.k.a. ORACLE_HOME) of an Oracle software installation. But what has not yet been added or discovered is a running database instance associated with that ORACLE_HOME.
Looking at that screenshot, notice that there are three bright green "+" (i.e. "plus" sign) icons? Those icons represent an "add" or "creation" action. The first "+" icon is to add another "dataset home" (i.e. ORACLE_HOME, PG_HOME, etc). The second "+" icon in the middle of the screenshot is to add an Oracle database instance to the ORACLE_HOME. The third "+" icon near the bottom of the screenshot is to add a PostgreSQL database to the PG_HOME.
So, is there a running Oracle database instance on that server? If so, can you refresh the "ls_dsources" environment, so that Delphix can try to discover it? To refresh the environment, please click on the green circular arrows that look something like the "ying-yang" symbol, in the bottom right corner of the environment card?
If a refresh doesn't cause Delphix to automatically discover the running database instance, there could be several reasons, so you'll want to add the database "manually" by clicking on the second (middle) "+" icon on the page. It will prompt you for database name, database unique name, and ORACLE_SID. Once that is entered, then you'll notice the new database entry as a new row, and two links to the right indicating "Add dSource" and "Show Details >>". Click on "Show Details >>" and add a JDBC connection string to access the database, and be sure to test that connection too.
Once all that information is added, then you should see the prospective dSource show up in the left-hand list in your first screenshot.
Hope this helps!