Can’t upload images to media file when making a post nor search for new plugins

Hello, I’m relatively new to www.remarpro.com

I thought these issues might be related so I’m clumping them together. I learned how to make my own blog site from scratch by following someone’s instructions online.

But now, whenever I try to upload a png image to the media file, It says “An error occurred in the upload. Please try again later.”
The media library stays constantly loading as well.

When I try to search for new plugins, it also just constantly loads.

They worked before and I was able to upload images and download plugins in the past. I tried disabling all plugins but the problem persists. Any insight would be appreciated.