How do we calculate the dose of weed?

My friend and I want to smoke some weed. We have 1 gram of 22thc 100s Super Lemon Haze. We want to smoke it throughout the day, but little by little. How do we calculate the dose for the first joint so that we don't get paranoid? We've smoked about 10 times, so we have a psychological tolerance, but still. Our physical tolerance is down to 0.