Welcome Carlyjee,
If you have frost coming, your fruit will not ripen anymore outside unless it is temporary. You should not pick the fruit green keep it on the stem. If frost is there to stay cut the stem with the fruit off and hang it in a cool, dry, dark place. Doing this still may not ripen your fruit. It depends on how long the fruit have been on the banana tree. Your tree has now fruited and will now die. So with this in mind you can save the pups which are the next generation. If they are in the ground you can dig them up and overwinter them indoors if it gets too cold outside. Good luck with your fruit and your start with bananas.
Valerie
