Hi Ganimede,
> 1. SQL> ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;
Logical standby databases are not supported in a SAP environment - please check SAPnote #105047 for further details.
> I have a question.... does DBUA must be start before or after that I re-anable dataguard?
This is exactly described in the mentioned Oracle documentation. The DBUA part is step "10. Upgrade the primary database as described in the Oracle Database Upgrade Guide. Note that the physical standby database(s) will be upgraded when the redo generated by the primary database as it is upgraded is applied." Anything before and after this step is exactly described.
Regards
Stefan