Is it possible to do this and are there plugins to help with this?

Question

css

You need to create an animation on the fullpage.js plugin without a scrollbar, and the animation should work when part of a long landing page fits into the screen.

Answer 1

fullpage.js and the scrollbar do not affect the ability to make an animation in any way, more precisely, they do not interfere with making an animation.
If you read the documentation for fullpage.js, here:
https://github.com/alvarotrigo/fullPage.js#methods
you can find methods like onLeave in which to run the necessary animations. Or even do it through css, since the script adds a class for the active section when you go to it, you can generally only animate everything you need through css