If they think that is what you want to hear they will all be "new" to the business. Also they "only work maybe one or two days a month to pay their rent". Or, they will try to convience you that they hate being a puta and "really want to find a gringo novio"!! That last part is often true in that they really do want to find a gringo who will spend "muchas plata" on them!! Finding a truely 'NEW to the business" chica is not easy. Almost always they will have been 'selling' it to Ticos for a while before venturing into the gringo market.
New to the business means possibly more GFE:
My experience is that just the opposite usually is the case--the newer, the less likely to be GFE or to give BBBJ, CIM, or even romantic! As for being less likely to have a STD; NO way!! They are much more likely to have been plucking their 'novio' or 'novioS' or even their male neighbors, or male family members, or even all of these combined, SIN CONDOM!! Being in the 'business' for a while tends to educate them to the risks of "sin condom"!!!
As for 'liking' their work! Some do. Some like the power it gives them! Some like the party atmosphere that goes with the business. Some are just plain Nymphos and can not get enough sex! (MY favorite kind!
)! ALL, IF SUCCESSFUL, WILL BE VERY GOOD ACTRESSES 
Many, new and old alike, will give the GFE if it means getting more (money) out of the guy or getting repeat business! They ALL NEED CASH!!, They all see providing intimate company to gringos as fairly easy money!! But they also find almost all gringos to be old, fat, smelly, vulgar, and repulsive; they just hide it very well or they do not succeed in the "business"
My advise: learn to "read" a chica just as she has more than likely 'learned to read you'!! Learn how to comunicate with them to get to know them and learn what to expect once the door closes!! This usually envolves learning at least some espanol!! Spend time "partying" with her if possible before going to the room to help "read" her. And most importantly, learn to NEVER think with the 'lil' head!!!. Lay your needs, desires, and wishes on the line before going to the room, and learn to read her responses! But do not occupy a lot of her time if you have no intention of 'taking ' her. Doing so only costs her money and wastes both of your time!!