We are confident in ourselves and are we open to new ideas.
You are both lucky you are inexperienced. This is because you can both learn new stuff together.
But you have to leave the insecurity out of your sex lives. Like you said you are open to new ideas which makes me happy. So, read books on sex, you can get the kama sutra book online which teaches the 101 of sex positions and how to get better by the day. Try new sex styles, just explore, always be protected and careful while having fun.
Also, don't have sex in one place as it can get boring. Try having sex on the stairs, on the kitchen counter, in the shower, in the car and other safe places you can possibly think of.
Below are some instructional methods to guide you on how to have better sex with your girlfriend.
Let your girlfriend get on top while you prop a pillow under your head so you can really see what's going on. It's going to be a great view while watching your girlfriend ride you.
You can also prop a mirror nearby and sit at the tip of the bed, with your partner sitting on your laps. Put your hand over hers and guide your hands slowly over her body and up her inner thighs, showing her exactly how much you like to please her.
Another thing to consider is communication. Make sure you tell each other your likes while having sex, what feels good and what doesn't feel right.
Trust me, there's a lot out there to explore, so take your time and enjoy your sex life.