Is going to navy a good choice after high school.. What are the advantages & disadvantages?

Yes, it will send you places around the world, teach you certain skills, and pay for your college after you get out.

Advantages:

Reasonably okay government job because the private sector is on the decline.

Support from the general populace, both liberals and "conservatives."

A government job that that can be endlessly supported with more taxes.

"Fighting for our freedoms."

Ten percent restaurant discounts.

Meeting thinner women overseas.





Disadvantages:

Intervening in other countries instead of defending the US.

Fighting for oil merchants and having US taxpayers foot the bill.

Fighting under false pretenses, as in no Iraqi WMDs at claimed by the US gov't.

Continuing to play World Policeman.

Risking a higher rate of homelessness as a vet over the general population (12.3% vs. 10.4%).

Risking a higher rate of PTSD as a vet over the general population (7.5% vs. up to 20%).

Risking permanent disability (a regular member here collects permanent disability from carrying a 80-120 lb. backpack).

Shooting a foe that was your friend last year (e.g., CIA funding the "good" rebels one year, but declaring them "bad" rebels the next year).

Thinking that you can only "serve" in the military when you can actually serve in any job or endeavor.

Fighting for purposes that have nothing to do with the US Constitution.

Regretting your decisions like many people who regretted joining the military (see list in comments).


Sources:

See the comment link for sources cited here and also a more complete answer.

If you score very high on your ASVAB and get offered good jobs it's a good choice. If not, join the Air Force.