Working multiple Step 1 exercises simultaneously

[ArtOfHands@...]

I am beginning the practice of Step 1 in IIH. I have started the
first Spirit exercise (Thought Control). While I am working on that,
can I also begin the Conscious Breathing exercises.

Also, must I finish all of the Step 1 Spirit exercise (thought
control, thought discipline, and mastery of thoughts) before I begin
work on the white and black soul mirrors?

Thank you,
Sarah