I don't think it's that unusual. When you brought it inside, the warmth may have triggered the flowering. Mine in a "cold/cool" greenhouse, usually bloom in February but will go out today to check for any blossoms. It has been fairly sunny, so that helps. Congrats.

So just let it do it’s thing? What about pruning? When I touch the fruit. Barley touch they fall off

Prune it to keep it shaped and small

I would leave it be..., it's flowering on the darkest day of the year. You can always prune in the spring. Not sure how small you want to keep it, it is a tree but they can be kept bonsai size if that is the goal.

Mines flower every month of the year if I have more than one tree.

I have two flowering like crazy right now

So should I treat it like a regular growing season? Keep it moist. Fertilize it? And why when I touch a flower or a lemon it falls off without barley any pressure.

Welcome to the world of potted citrus trees. My New Zealand Lemonade tree flowers like a Meyer lemon does. For my tree If I let it flower it sets fruit and continues flowering. The fruits grow while the tree keeps producing more flowers. As the tree continues flowering the tree starts dropping developed fruits followed by leaf discoloration/dropping. My lemonade trees keep putting on new flower buds. Branches start dying back and even more flower buds are produced. I left 2 NZL's alone and in 6 months they both flowered to death. No root rot or soggy or even dried out soil. I don't know if Meyer lemons do that. I remove all flowers after July as soon as the buds are visible, and the trees do fine.

It is not at all unusual, especially for citrus grown indoors, to flower in winter. And as noted, some species bloom intermittently all year long.

Enjoy the fragrance while we can while they are inside. I sure am. Pics to come soon))