It goes into the "resourcepacks" folder :3

For resourcepacks I love reimagined by Reijvi, and stuff like bushy leaves and bee's fancy crops, as for mods my top 2 vanilla like will always be supplementaries and quark (long time since Ive seen quark so idk if its outdated or what)

a lot of them probably used resourcepacks that change non-hardcore hearts to look like hardcore ones