cartoon animations

Hi there, I am new to video editing and want to produce videos for kids. I am looking for a low budget solution to add cartoon animations to my videos. as a reference, pls see Vlad and Nikita build Playhouses best series for kids - YouTube. I assume there are libraries / presets that i can buy online and put in my videos. I am using imovie so what I buy should be compatible with that. Could anyone point me in the right direction pls?
Thanks
Till

Maybe something like this would work?

Amazing stuff! Thanks so much for this. Do you know if those can be used in iMovie? Cheers

I’m not 100% sure but it seems like it would work. I would ask in the comments of the item so the author can reply to you and others can see the answer as well.