yes, it is OK to run it all on a single circuit, but I would not do it. I would separate them up. Kitchen and dining room on one, both bedrooms on one, and the bathroom hallway and living room on one, and the porch on whatever room is closest (normally the living room). Running all these with 14/2 is fine. If you want them all on a single circuit, then I would go with 12/2 just to cover bases.
You can calculate the wattage and get your total amperage, but you would need to have all of your fixtures on hand to get the wattage. there is a conversion that I do not have memorized, but you can get it in an Ugly book and then you will know if the total amps used would require 12 or just 14. Breaking it up to 3 circuits will make it better. Plus, you do not want every light to out in the house if a breaker pops...