It has been many years since I last extensively used Garageband. I used to use it to make videos, and sound effects and foley were very useful. But, that was 15 years ago. Does anyone know where those effects went? I have some in Final Cut Pro. Should I use those?
I just remembered... Can't you go to the Garageband menu and choose "Download more sounds" or something like that? I'm not at my Mac at the moment, so I can't look, but I think it's there.
I used to use Apple's "Soundtrack Pro" software for sound effects. That was a very good piece of software (which Apple eventually abandoned), but not really made for musicians. I think it basically became redundant because Final Cut Pro has it's own sound editing functions. If I were you, I'd use FCP.
You should be able to download all the currently available content for Garage through the application. I forget how it works for GB though, but on Logic Pro there was a place for Legacy downloads, meaning all the older material that was discontinued with current versions. I use GB for creating jam tracks but I never much liked Logic Pro. But there are many, many sites online that offer foley material free. To find them, just type in a search like "dog barking audio download" or "car horns mp3 download" and you should have many options. I typed in "children cheering audio download" and this one of many sites that popped up:
https://audiojungle.net/category/sound?term=kids%20cheering -- but of course the days of free stuff on the Internet is over, so if you have to pay, like here, you find another site, or you can use some sort of audio capture software, like audohijack, or use your screen capture options and capture the audio that way... for free.