As Andy mentioned a while back, https://www.jukedeck.com and https://www.audioblocks.com are also good. Audioblocks is $99USD per annum but has a great selection, including sound effects. Jukedeck keeps crashing when I use it but it is free with attribution or 99c per download without.
There’s also Kevin McLeod’s site at http://incompetech.com/music/ I like his stuff, his tracks don’t sound like they were made by robots 🙂
Sound effects are easier to find – do you want crows? crackling fireplaces? flushing toilets? howling dogs? It’s all there…