Your reseller is a good place to start

We offer many courses to show you how to create your own reports using Sage Intelligence Reporting.  The beginning course is a recorded Anytime Learning course that you can access at your convenience.  You would then register for the Intermediate course.  You can find all courses by clicking here

New inventory reports can be based on a Sage report (customized), a new custom report (run from Sage menu), external report (SA&W, Visual Cut, Tableau...), Sage Intelligence, Excel query... there are many options, depending on your skill level and what you need.  Consulting with your Sage Partner / reseller first is a good recommendation.