(Laughing) One of our running cadences useta be "Hey young soldier, don't feel blue- my recruiter was a liar too!"
Actually, any promise that a recruiter makes IN WRITING must be met, or you are released from service.
As far as "Can I go to Basic Training without being a member of the service?"
No. Unqualified NO. Illegal. Can you get a small taste? Yes. Check schools in your area for a Junior ROTC program.
Your best route to military? Get into top physical condition, and stay there. Next, study like hell, make good grades, graduate top of your class. Most services require a minimum of a high school diploma. Was not always like that- I was a dropout, got a GED while in service (and a few degrees since)- but times have changed.
Some folks think the military looks for dummies that can't do anything else. Consider that a rifleman has a night vision scope that costs $8,625. A Javelin gunner (FGM-148 man portable Anti-tank missile) has a tracker that is $125,000, and each missile is $40,000.