For each query where you want to get the totals, build another query on that one.
Example: Query1 has fields Category, Date, SalesValue
New query -- add Query1 to the data sources.
Drag Category, Date, SalesValue onto the grid -- but do SalesValue TWICE.
Make the query a Totals query by clicking the Sigma button on the toolbar. This gives you a Totals line in the grid. Default is Group By for each field. Leave it like that for the first 2 fields. The first SalesValue field should have Count in that row; make the second SalesValue Sum. [You could add a third SalesValue, and make that Avg if desired].
HTH
Denis