The cherry refers to the Hymen - a ring of tissue surrounding the vaginal opening, but not covering it completely. There is a common myth that a woman does not lose her hymen (cherry) until she has sex for the first time. So "pop the cherry" refers to the hymen breaking and the bleeding that may occur (but does not have to) after sexual intercourse. The hymen does not always get stretched or torn during the first experience of sexual penetration. Many females tear their hymen through tampon use or physical activity such as horse riding before their first sexual experience.
TeenHealthFX thinks that you should not do anything that you are uncomfortable with or are pressured into. At 14 you may want to wait awhile before engaging in sex. This is a major life decision and one that you need to be comfortable with.
Finally, the comment the boys in your class made to you were inappropriate and rude. If it happens again tell them that you do not appreciate their remarks and if they don't stop, tell someone who works at your school.