I think it might be worthwhile for you to spend some time taking the on-demand training or viewing the Marketo documentation online. To learn more about channels and program statuses, you can
find more information here. There is also a comprehensive section on program and program membership
here.
BTW, those numbers for the steps are not scores, they are the steps of each program status. The Step number is used for sorting of program statuses. Leads cannot go backwards in these program statuses - only forward.