You are asking us to decide for you about whether or not to take on a job that sounds as if it is more the cover for escort work than anything else. Your friend is working for a travel agency that provides sexual favours, presumably for businessmen and wealthy clients. It's not for us to tell you how to behave, it's for you to decide for yourself.
How do you feel about taking on a job where you will be expected to have sex with men (maybe even with women) in return for payment, either in kind, or directly in cash? How do you feel about having sex with a guy in order to get the job in the first place? I suppose I should be shocked that in this day and age, women are still forced to have sex in order to get a job, but in five years of being an editor on here, there's very little that surprises me these days. People continue to behave in the most selfish and arrogant self-serving ways, and a man in a position of power still uses it to get what he wants all too frequently.
The fact that men use their positions of power in order to have sex with young girls is an unfortunate fact of life. If your country doesn't legislate against these things, and make laws (that are rigidly enforced) to prevent this sort of thing happening, women will continue to be the victims of sexual abuse and rape. In the West, men finish up losing their jobs, and serving prison sentences, for forcing their sexual demands on a woman, (or man) and companies don't hesitate to fire a man or woman who uses a position of power in order to force somebody into a sexual activity. But it's not like that everywhere in the world, and you are in the unfortunate position of having to decide whether you think it's worth it.
Is the money more important to you than your self-respect? Make no mistake, most of the men that need to go to the extent of using a travel agent who provides compliant women are the type of guys that you really should be steering clear of. Okay, you might meet some interesting foreign men, if you're lucky, who may well reward you with significant amounts of foreign money, and may even treat you very well, as both a sex partner and a pleasant companion during their tours, but on the other hand, it's not like you will have a choice of who you do and don't sleep with. The decision of who you sleep with will be made by your bosses, and in this situation, they would be little different from a pimp who controls his team of prostitutes working in a brothel.
Virginity has nothing to do with this, beyond the fact that it means you are very naive about sex. You will lose your virginity at some time, whether it's to a boyfriend, or to the guy that you get married to. Your virginity is really only an obstacle that causes a moment or two of pain, then it's gone forever. But I would have thought that if you are going to give up your virginity, it should be with somebody you love, or at least someone that you like very much. Not some guy who is using sex in order to grant you a favour that leads to you becoming little more than a prostitute.
Your friend obviously found that she could accept having sex with a man in order to be well paid, and, as you say, continues to have sex with men for payment, and probably because she hopes for promotion within the company you are considering to join. She made her deal with herself, and found the terms acceptable. If you look at those terms, and you find them acceptable, then there's nothing to stop you. But it's no good asking us, you have to ask yourself what you think is right, or at least what you think you can accept.
Whatever you decide; before you commence having sex with anybody, go and see your doctor or the family planning clinic, and get yourself a recognised form of contraception. Don't do what thousands of silly girls do, and have sex, and then take the i-pill the following day. If you decide that you want to start having sex for some kind of financial reward, go into this business with your eyes wide open, fully prepared, and protected against the possibilities of pregnancy and sexually transmitted infections; if you choose this path,, I for one won't criticise you. All of us face difficult choices in life, in one way or another, and this is a difficult choice for you. The choice you face is whether you give up your virginity to somebody that you don't know, and may possibly find extremely dislikeable, and then go on to have sex with people for financial reward, or whether you pass up an opportunity to earn a lot of money, and continue to struggle to make your way in life. The thing is, you never know what's around the corner, and I'm sure that other job offers may not come with the same kind of strings attached. Just because your friend is doing well from it, it doesn't mean you have to follow her. However, if you think this is an acceptable price to pay, then go ahead and do it.