Welcome to our forum.
Sounds like you've made a very positive foray into polyamory and picked out an excellent couple in doing so. Nothing so sweet as growing a romance with long-time dear friends.
Anything new tends to be scary even if exciting, so it makes sense for you to join Polyamory.com and learn a lot about how poly does (and doesn't) work. Communication is perhaps the biggest key, so if you communicate well with each other then that's a hopeful sign.
We have a Golden Nuggets board
that might prove useful to you, it covers a lot of bases about what you need to know about polyamory. And, you'll find helpful hints scattered throughout our threads and boards. You can do searches, tag searches, and of course post anytime you have a thought, question, or concern.
Hope you enjoy your time with us; good to have you aboard.