Hi,
About your LO steps, after Step 6, you need to schedule V3 job(hourly job) in LBWE-->Job Control.
Run init without transfer
After that you have to just run delta load
1.to activate extract structure which tcode i need to follow lbwe or rsa5/rsa6?
Firstly, you have to install from RSA5
Activate the extract structure and generate the datasource in LBWE
2.using extract checker i can check data in extract structure. yes/no?
This will show the data for all the fields of your extract structure by pulling data from the database tables.
3.when i need to install business content?
This could be step 1 to use any LO datasources.
4.did sap given std data flows?
Lot of standard flows are there. You can check in help.sap