Where do you sell your stuff

I am looking for a app or a place to sell all my used stuff

I have tried offer up I used to sell so much on there before all the updates and let go but now there's like a bunch of stuff and no one is buying on that app.

Facebook looked good to sell but the Facebook sites are a mess! There's no just kids used stuff for sale I'd like to create a page do you know how? On Facebook create a group for moms to buy and sell used kids stuff

Where do you recommend to sell items.