confusion and frustration

I was learning Juniper and when trying to follow the lab from time to time it would turn into disapointment. Instructors would create a lab and sometimes base future lab on previous sometimes start from zero. But with in time I realized that there is script that is not mention. When something does not work I do deep investigation and realize one can not work with out the the other and it be some chunk of script that is not mentioned in lab.
For example in Juniper JNCIS-Route (JN0-351) with Aaron Gould in lab for agrigated route he provides only script related to the topic but the lab involves OSPF and BGP. Those 2 topics are way ahead of this topic. 1st it would make sense to teach agregated route after them and 2nd provide full script so when I try to recreate the lab and learn by doing.
Certainly I have done research and created OSPF and BGP connection but now confused how do I plug in the script that Aaron provided relative to the topic he teaches?
And like that I was struggling with 3 course.
Please do something to remove this confusion. Otherwise I see no difference than just using vendor's free tutorials.