Im 19 yrs old and my girlfriend(also 19) is a virgin how can I get her to have sex wth me?

you can ask her. but if she says no or she's not ready you need to respect it.

Definately. Ask her. Just do it smoothly. Kiss her and tell her how much you care. Tell her you love her and cuddle. Maybe give a back rub. A massage. Then ask her. But be a gentleman about it. :)

Welcome to my 4 step program on how to ask a girl to have sex with you.
1. Get MARRIED!!!!!!!!!!!!!!!!!!!!!!!!!!
2. Take on date.
3. Ask if ready.
And finally #4. Wait if not ready or if ready choose a quiet place (hotel,bedroom) then do it.