Hi @shaikhshoeb ,
1. Happens automatically, you're only part of the reporting if you enter the activity/sees one of the experiences.
2. Not necessarily, you could define the conversion as seeing a URL. If it is an order with a value i would implement an orderConfirmPage mbox/call. This enables you to use revenue as a metric for your activity. If this isn't the case I would just simply specify the URL:

3. I would again use conversion and select 'clicked an element' and then select your element. This way you avoid having to implement further calls.

Yes you can configure several metrics. You have your primary and just below that you have 'additional metrics', click 'add a new metric' and you have the same options available as for your primary one.

Hope this helps!
Kind Regards,
Kasper