Welcome to our forum.
I would take things slow for now, the speed of the slowest person. In other words, let your girlfriend set the pace. Also, you have a tough balancing act to perform. Balancing your time and resources between two partners isn't easy. It's easy for someone to feel they've been forgotten or given an unfair share. So, slow, and learn as you go along.
Take advantage of the wealth of threads this site offers. The Golden Nuggets board
might be a good place to start.
Post any thoughts, questions, or concerns you might have. For the moment, just take things slow and see what happens.
What kind of relationship do your girlfriend and ex have? Have they met?
Hope this helps,