A revert who wants to marry his girlfriend

DWQA QuestionsCategory: WomenA revert who wants to marry his girlfriend
Ben asked 5 months ago

ASalaam! I reverted to Islam last week and want to pursue a spiritually fufiling life. I have a girlfrind from before the reversion who I love dearly and is Catholic. She has been very supportive of my faith and encourages me to pray and follow my beliefs. I wish to continue our relationship in a lawful way and want to propose that we sign a nikkah, detailing our expectations for each other but delaying the ceremony until a time that we feel more stable and prepared and are living in the same place (our relationship is currently lono distance). Is this valid approach? Could you provide textutal evidence to support the claim? 
I’ve also read that a Nikkah needs to be witnessed by two Muslims. Because I recently reverted I don’t know any muslims yet, and live in a complex place where it might not be safe for me to go to a mosque. Is it possible to have witnesses online, through a forum like this?
May you have peace and blessings for your help!