Bday tickets can be acquired at the birthday date you've input into your PSN account.
Via trades or creating secondary accounts.
Level tickets can be obtained doing "Seasonal Races"
Trades or once you complete A-spec or B-spec Beginner and such, Completing all Beginner gives you a Level 5 while Endurance is 24. Heres a link for every prize obtainable in game. https://www.gtplanet.net/forum/showthread.php?t=134047
To answer another question I've seen.
I always save my GT5 "Save Data Utility" unto a USB stick prior to Gift the ticket, or a car, then I reload from the USB saving device. The ticket or car will remain afteward. Its called duplicate around here but make sure you are cautious in the process. You could loose your garage if not made properly. I dont wanna be held responsible for any mishap.
