Hi Ricardo,
Congratulations and don't worry too much about LRII. S/he's forgotten how good that first jet job feels
Just some thoughts that might help you:
Do pack the extra shirts
Flying makes up about 10% of the work bizjet jockey's do. Managing the passengers, catering, fueling, baggage, handling agents, slots, delayed flight plans, etc. is a lot to learn so watch the person in the left hand seat who's been doing it for a while.
You will be going into all sorts of airports that you've never been to before so take some time before the flight to go over the Jepps and read EVERYTHING on the plate.
The captain will have a lot on his/her mind so try offering him/her a tea/coffee while s/he is doing the paperwork at the end of the flight.
Last but not least, enjoy it!
Cheers,
Chips