first timer moving potted plant from outside to inside

I'm moving one flowering plant from outside to inside to finish it off. I got a 1-mo. late start and it starting to get into the 40's at night. I need to move them inside have no idea what I need to do - lights and timing to increase yield, nutrients, etc. So far, I have not fertilized it at all - just grew it in potting soil. It's my first plant to ever get to this stage and I don't want to hurt it. Thanks for any help.