Can I use free adobe stock video and images for Youtube videos, to make ad revenue as well?

You can use the free videos in the same way you would use paid videos. For any commercial or non-commercial use, there is no difference between paid and for free assets. The licensing terms count.

Look here for more information on licensing: https://community.adobe.com/t5/stock/links-for-licensing-terms/td-p/11366788
(Disclaimer: As always with licensing, this is my interpretation of the rules. I think they are correct and advice is based on reading and interpreting the licence terms and on fair use for both the buyer and the artist/stock company, but I cannot rule out that my interpretation is wrong. I'm not an Adobe employee).