You are told when you start your world that the addon is installed. you can see the current points and time left at the center bottom (along with a little heart that beats as you play. it gets fast if time is about to run out)
just about everything in the game gives you points the first time you see it. and when you hit a new high level you get extra time to play. it adds up quickly in the start
The mobs in the game offer the largest quick gains in time and points generally speaking. anytime you hit a new area be sure to look up the unique mobs and get lots of points and time.
if you can get near a special item, mob or block there are HUGE bonuses to be had. the bonus is retroactive as well! If you are near an ocean and have some milk to remove the curse, getting close to the elder guardian is prettty easy to do.