Go to https://images.google.com to reach the Google Image Search page. Enter your search words. From the results page, click on "Search tools":
Notice the additional search filters that have appeared. By clicking on "Labeled for reuse", you can filter your results by license type:
Go to https://www.youtube.com to search for online videos on YouTube. Enter your search words. From the results page, click on "Filters":
Notice the additional search filters that have appeared. By clicking on "Creative Commons", you can filter your results to only those with a CC license: