You can view ad campaign reports after your ads start displaying. Click on View statistics on the campaign page. If you check these statistics regularly, you will know how well your ads are performing to bring users to your site.
In the “Search queries” report, for example, you can see the queries for which your ads were served. To prevent Yandex.Direct from serving ads for non-relevant searches, use negative keywords. You can add them on the page where you edit your campaign or ad group.
You can get detailed statistics on all your campaigns and evaluate the effectiveness of specific keywords and ads by using the Report Wizard.
Read more information about campaign statistics.