It's not a single leap from reading no one to reading everyone. Rather, it's a process. One way you can start improving is to pick a player or two and try to guess their hands, preferably every hand they play, not just the ones against you. Watch for what they show down with after limping, calling and raising, and in which positions.
It can also be a useful learning exercise to watch games you'd normally play in, or that you just busted out of. As above, start out by trying to figure out how a couple of people play, not the entire table.
Loose players are harder to read because they play more hands, which means they have broader hand ranges, so you might want to start by choosing people who are tighter and thus more predictable.
