Will Video Background affect my SEO negatively?

As the Google algorithm works is not public, you may usually find many opinions on what is good or bad for SEO.

About videos and SEO, we find this article https://www.seoblog.com/2018/03/autoplaying-videos-hurt-rankings/ really qualified because they're SEO experts and the article includes a response from Google themselves:

So, as far as we know, videos don't penalize your Google rankings.