There are two ways to access your exported files:
1. You should receive a notification confirming that an Export file is available for download. Click on the Notification Bell in the top right corner and the file should be available for download there via the downward arrow button.
2. To view more detailed summaries of your Site's Exports as a List you can use the 'Export Summaries' App in your Site Settings Area. See how to do this here.