Originally Posted by WWGuy

Here's how it works at every company I've ever worked for or with:
1. Get job.
2. Work hard.
3. Earn money, respect, and vacation.
4. Request vacation time from manager.
5. Book and enjoy vacation travel.

Any exceptions should have been discussed with the recruiter or HR manager during the interview and new-hire negotiation process.

By his own admission the OP jumped straight to step 5 in an impulsive moment after getting the new job, but before starting it. He's now trying to learn how to best accomplish step 4 without much apparent consideration for steps 1 through 3.

Count me among the managers who would view this as thoughtless and perhaps disrespectful, especially for an inexperienced entry-level employee who hasn't demonstrated previous history generating value for his employers. Booking non-refundable travel in this situation also shows lack of critical logical thinking skills. If I was the OP I'd keep that information to myself when approaching this subject with my new boss.

OP is doing the right thing now in realizing this may be a delicate issue and in seeking advice.