Following a Teacher
When you follow someone you automatically follow all of their Boards, including any Boards they create in the future. Anything they pin to a Board will show up in your home feed.
Following a Board
If you are only interested in one ore a few of someones Boards you can choose to only follow those specific Boards. This means you will only see Activities they pin to these Boards in your home feed
Who Should I Follow?
You should find people who are teaching similar classes and material as you. This could be peers at your own school or even a teacher in another state. Whenever you follow someone, new material they create or pin will show up in your home feed.