Where do I find Video/Lottie Animations?

What is a good website to find 3d assets such as those used here:

The rose from this tutorial: Web animations with After Effects & Lottie | Webflow University
The background video used here: https://webflow.com/website/TRICKS-Glassmorphism

Hi, try https://lottiefiles.com

Tried, it only has really plain vector animations not those similar to the links I posted.

The more advanced animations are often created in Adobe After Effects and converted as described in this Webflow University course.

Also, there are lots of After Effects projects that can be tweaked to fit your own content at sites like Envato Marketplace

Hope that helps.