I'm assuming you're not sure where to even start with this since your question is very vague (this is why you're being downvoted).
A good starting point is obviously using the standard SO Crystal Report Layout in the system and checking off the "New Page After" option in the Details section of the Crystal Report (this will create a new page after every line item). Then modify the format of your Page Header and Footer to accommodate your "Proforma Invoice Copy" requirement.
Give us more detail of where you're stuck and maybe we can be more helpful.