Hi Cattle Class and Welcome

If you have booked your flights direct with VS then all you need is your booking ref, date of travel, lead passenger surname and flight number.
go here
https://www.virgin-atlantic.com/find_booking.view.do to enter the info to bring up the booking details including seat maps/special meal requests.
If you have not made the booking direct with VS I guess you will need to contact the booking agent and ask them for VS's booking ref - I beleive bookings made via VH that include VS flights can be seen online using the above link [?] Someone else may be able to answer this better than me though.
Otherwise I suggest you give VS a call, you will only need your date of travel, flight number and lead pax surname if calling.
Failing that why not join FC, add your new flying club number to the booking, then your booked flights should be visable online

Regards