[Maybe a free video/audio assets category would be nice on these forums? ]
I know good legal and free sound effects too – https://www.lucidsamples.com/free-sample-packs/181-free-sound-effects-sfx-pack.html
You will find some really professional sounds on this website: http://www.ogsoundfx.com
You’ll find some free sounds especially if you subscribe to the newsletter (and stay subscribed because it’s the best way to get privileged discounts and more free sounds)
Another useful resource for video, music and vfx/sfx is
Once you’ve signed up to their mailing list you are allowed 5 DLs a day from their site which is full of high quality material. Half of their stuff is available for free DL, the other half is reserved for paid members but the free selection is full of useful items.