Got confused with this topic. I've AP & AR module. When i post the transactions, will accounting entires will get created in primary general ledger or i will have to select create accounting ? How does create accounting process knows that it needs to create entires in reporting ledger?

You enter transactions in AP and/or AR and run "Create Accounting" program in both the subledgers separately. The accounting will be created in the GL. If you have created subledger level reporting currency then the Create Accounting program will create accounting in reporting currency ledges as well, automatically. If you have created journal level reporting currency then the transactions will be replicated by the posting program instead. When you post the journals in your primary ledger, mirror journals will be created in the reporting currency ledgers. All these details are covered comprehensively in the videos.

Thanks and appreciate the response