dropping and recreating index and tables

I have error ORA-00600 involving indexes and tables.

As for the index, the general consensus is to drop and recreate it.

First, I was able to connect to the db using SQL Developer. And I was able to navigate to the related index and click on SQL. That is the SQL needed to re-create the index, am I right?

How do I get the same SQL command from via SQLPlus?

Should I need to backup the index before dropping it, the Export function exactly do that, right?

Is there also ways to do the same via SQLPlus?

Table.

I know tables contain data.