Way to learn BigData

Hello,

I have subscribed to simplilearn combopack for bigdata(90 days access) that includes below courses:

Big Data and Hadoop Developer.
Big Data and Hadoop Administerator.
Apache spark and Scala.
Mongo DB developer and Administerator.
Data science with R, SAS and Excel.

Currently, I have started "Big Data and Hadoop Developer" course which is going to finish in next 10 days. Now my questions are:

In what order should I pick further courses for better understanding?
Is it worth to learn...

Way to learn BigData