As the above posters have indicated, your entire GPA will be calculated.
All of your info will be sent to an organization called LSAC. They will calculate your GPA based on every college class you've taken, whether at a community college or four year university. When I applied I had a handful of individual summer classes I had taken at a couple of different community colleges, and those were required to be reported and were factored into my GPA.
LSAC will then "weight" your GPA, and it may go up or down a little. I'm not sure what formula they use to adjust your GPA.
As far as the LSAT is concerned, just shoot for the highest possible score. There is no magic GPA/LSAT combo you should strive for. The higher your score, the more options you'll have.
Lastly, as some of the other responses have said, law school admission is primarily a numbers game. People spend a lot of time obsessing over how to present soft factors like grade trend, volunteer experience, or study abroad, whatever. At the end of the day, the vast majority of decisions will be based on numbers, period. With a 3.19 GPA you can still get into many ABA law schools provided that you score well on the LSAT.