Analysis help with 4 data sets comparing with 1 dataset, but I have 70 variables to identify key focus.

[#1]

If I have 4 data sets comparing with 1 dataset, but I have 70 variables to identify key focus. What are the steps for reducing variables to get to the few key variables affecting my results?

I was trying out using Z-Score Variance Filtering, to reduce down to 20 variables, then run PCA Analysis.

Are there other ways to do this to be more accurate without JMP PRO?

[#2]

Welcome to the community! It will be easier to answer your question if you can give a bit more information. What are you trying to accomplish? Are you trying to compare these 70 variables between the different datasets? Are you trying to understand how these 70 variables influence a certain outcome or response variable? 

As a starting point, you might want to read this summary of the Multivariate Methods available in JMP.