Look for a yoga class with power, core, ashtanga or vinyasa in the name. Avoid hatha.
I was not born with an innate knowledge of how to do yoga :)
I recommend finding a class that speaks to you. A good teacher will make you get the right focus and postures.
That does not mean practicing by yourself is a safe or healthy alternative.
If you can't find good teachers in your city, do something else. But please don't blame a whole discipline for the poor quality of teachers and students.