A virgin is someone who's never had sex. People define “sex” and “losing your virginity” in different ways. Don't feel pressured, wait until you are ready.
Losing your virginity can be a big deal, regardless of your age, experience, and the research you've done (though it doesn't always have to be).
Not all of us lose our virginities at age 16 in the back of an old Camry. If you're still a virgin later in life, it can feel like you're the last person on.