Man, don't pay for it whatever you do. Your first time is a very emotionally charged experience and if you do it with a prostitute, you better have an extremely strong mental composition or it will fuck you up big style.
Remember, to these girls YOU ARE JUST ANOTHER PAYING CUSTOMER. No matter what they tell you before, they will be in a hurry to get rid of you the very second you "finish"...
Although I am sure you feel left behind by the "pack", you are only 19. You have plenty of years in you