[Start date] and [Last date] in a query
If these are fields in the report, then you can use them as part of a report title or something that defines the range in a calculated textbox; e.g.
= "Sales From " & [Start date] & "to " & [Last date]
Since the fields are in the query, you can easily add them to the report if they're not already on it - just hide them as they're probably not necessary to the user.
EDIT
If hidden, you can also make them very small so as to not take up space. Also, I would not use separate fields to construct the info line because the values will be different widths at times, thus alignment becomes a problem. If you put the entire line of information in one textbox, it won't matter if you use numbers or words for dates:
Monday, May 2, 2020 will align and fit just as nicely as Thursday, January 25, 2020 but not if you place one date textbox beside another.