Light flashing in bottom left of dashboard on a ford focus automatic, orange light, and the car is shuddering when going slow, any ideas?

Any time you get a light on the dash,of any vehicle ,you need to check your owners manual.
Next ,you need a code reader or better yet,a scan tool hooked to the vehicles diagnostic connector, under the dash to check for codes. I am really suprised at the hundreds,if not thousands of people that don't know that.
The vehicle symptoms will be found, after your have a code(if any) and follow some type of testing proceedure.