If you have taken the CD based training for Query Studio, then you will not really learn anything new by attending the classroom training too, as the same material is covered.
For Report Studio, things are a bit different. The CD training for Report Studio only covers the basics of reporting, and is equivalent to the first day of the 2-day "Report Authoring Part 1" course run in the classroom. There's also a "Report Authoring Part 2", which is another 3 days of advanced classroom training not covered on CD.
Bottom line is no further Query Studio training required, but you may benefit from the Report Authoring 1 and 2 courses.
Regards,
MF.