I want to write a program which when given two data sets, should be able to tell whether the data sets differ significantly or are roughly similar.

Details on the two data sets:

 - Both data sets will have same number of values.
 - A value in a data set may not be related to other values in the same data set.

Aim is to get a final score which tells about 'similarity' of the two data sets.

I am completely new to statistics. I am trying to learn AI and feel that this will be a good basic start towards Data Science.
Also, I want to visualize this.