I am 17 years old and want to get into the WOFT program for aviation after I graduate. Any advice for me being only 18 when I join?

The private pilot's license will certainly look good for your packet. Just work hard and don't rush your flight packet. Take your time and make sure there are no mistakes. If your packet is strong, you will be competitive against those who have time in the military.
Good luck!

I was only 17 when I enlisted.

Your age is not a factor unless you allow it to be. If you do your best you will do fine.

For all about to enter do what you are told, when your are told, and how you are told.

Confidence, not arrogance is the key. Currently the Army is short flight slots. You havent mentioned you physical status (Fitness, eyesight, prior health, hearing, etc.)
Dont skimp on you packet. Figure what deadline you would like to submit to, and make sure its complete. Your packet is YOU . your photo should emulate the standard ARMY look (not rank/ribbons, but blue blazer/sportcoat) you want them to visualize you as an Army officer, and you want it to be a positive image. You dont need a crewcut, but hair should be within regs, face shaved , etc.

I have a buddy that was a street to seat from HS and my son is currently in WOCS on street to seat (college).

If you can convert any dual credits from High School, or your flight training into a Assoc. degree then DO SO (even if it is underwater basketweaving) , if you are enrolled to get the assoc you can state (currently pursuing with grad date of.... and current GPA of ....) . On this note if you are fair test taker DANTES and CLEP are your friends. If you have a few credits already, with DANTES/CLEP you can complete a Assoc. degree in a few months.

LORS take your time, make appointments and impress the folks that are going to write yours. Oftentimes community leaders (Mayor, County Judge, Sheriff, etc.) are prior military (in my area for example the mayor is a retired 2 star, and the political club president is a retired navy mustang). These folks are fairly easy to get an appointment with and if impressed will usually write the LOR for you.
Your recruiter is going to be your gateway to the program, ask if they have done a packet before, was the candidate successful, etc. If they haven't done one, there is no harm in finding a recruiter that has accomplished this. Its a ton of work for the recruiter too, and they really dont get extra "stats" for street to seat.

Batt. Board: They want confident candidates for flight slots. That's confident, not arrogant. If you dont know the answer, say so. If you take a position, be confident in it. You can say "As a civilian and not knowing the particular regulation, I would do "XYZ" unless it conflicted with that reg"

After Batt. Board Have your recruiter double, triple, and quadruple check that all required docs made it Nat. Board. This will keep you from having to wait until next selection board.

All I can think of at the moment