Dude, your mentality that ‘every girl’ is taken is self pity and negative. Always be positive bro!
If the girl has a bf then move on man…no biggie. The only way to succeed is to go out and meet chicks…that’s all there is to it.
Also buy a good cologne, I got lucky and have Unforgivable by Sean Combs and it rocks. There are plenty of great scents out there…go yo Macy’s and head straight to the men’s cologne section.