Design , Config, NWDS and Flow of messages in SAP PO 7.31

Hello Experts,

I am assigned to File -> SAP PO 7.31 -> ABAP Proxy Scenario. I never worked on SAP PO and searched to find the related stuffs but nothing really helped me.

I am just perplexed to start from unseen boundary.Hope to receive some support from the experts.

1. Where to create DT , MT , SI and other design objects. Should it be there are NWDS or at SWING UI.

2. What about the config objects?

3.Any sample scenario tutorials so that it can shed some inputs.

4. Just then, whats the flow of messages in the SAP PO...

5. Any real time questions which can hit my continuous stream of queries. 

Thanks

Rebecca