Storyblocks is a subscription only feature which can be accessed as follows:
Find and preview stock content
Open the Explorer window.
Expand Vegas Content and click Video or Audio.
Enter a search term in the search box.
Review the results on the right side.
Point to a thumbnail to show the available actions.
Click Start Preview.
Watch the preview in the Video Preview window.
Download stock content
Point to a thumbnail to show the available actions.
Click Download.
Choose the file format and resolution that you want to download.
Wait until the download is complete.
The download area at the bottom of the window shows the current download progress.
Find downloaded files
In the Explorer window, expand Downloads.
Click Video or Audio to open your downloaded files.