If you want to run a report but can't see the report template you're looking for in the list of available reports, it's likely because you're not in the correct context in Landscape to run the report. For example, if you are trying to run a report that has a category of 'Site Visits' (like a monitoring report), then you need to navigate to an individual site visit record and then click on the report button. Alternatively, if you have an 'Issues' report, then you need to first navigate to the issue that you want to run the report on and then click on the report button.
This context is set by the report category. More on report basics here.
More on running reports here.