There are many dedicated social media sites and other websites where you can find lots of design inspiration. 

The two most prominent social media networks that I’d recommend you to check out are dribbble.com and behance.net. 

Other useful and inspirational resources:

• Figma community files – See all community files from Figma users
• Muzli – Get design inspiration when you open new tabs
• Awwwards – Discover award-winning designs
• UI Jar
• Collect UI
• Dark Mode Design
• Product Hunt

In addition, there are lots of personal blogs that write about design, more than could be counted. If you’re interested, I have written a bunch of articles about UI design on my website as well.