You do
not want to be in the right part of any lane if you intend to turn left.
You need to plan your turns ahead of time, signal very broadly to cars, and be aware of all cars to your left, right, in front, and behind you. A mirror can help.
Sounds like you should read up online a little bit about bicycle traffic safety...it's a pretty big subject, but one that your life might depend on.
Google is your friend!
