Complex Criteria - Error Messages/Issues.

When I try to save my criteria I get an error message "Please choose a question is Step 1"

This error usually means that you need to select a question that you want to the criteria to be based on. You can choose any multiple choice/numeric question in your survey.

I get an error "Please select at least 1 choice to filter" -- What does that mean?

You must choose one (or more) answers to filter on for the question you've selected to build the criteria. If you choose more than one answer, the system will automatically "OR" the multiple options i.e. the criteria will match if any of the selected options are chosen by your respondent.