That's my favourite. On this site you can find all kinds of content that you can think of. There are plenty of free designs available.
I'm sure you'll find something you'll love in more than 280,000 vectors.
Icons with great designs.
Freepik is my favorite, but it's impossible not to fall in love with the photos on Pixabay.
You can find everything from Logo to icons, Mockups to UI designs.
I'm not saying anything about this site. You absolutely must know, the father of stock photos and vector sites.
You can often come across poor quality content, but when you do a little research, you'll find great designs.And there's a built-in editor.