Best Practice for File Upload then Referencing

This is not urgent, but I have been surfing around the internet trying to figure out what the latest bleeding-edge technique for file uploads (lets say a pdf or an img)to my server and then referencing/using those files for the site (think admin portal to upload team headshots, or pdf’s of job descriptions for the careers page), and haven’t had much luck in finding it. So, question for you lovely folks: What do you use?
To be extra specific, I am looking for all the required steps/tools/techniques, both client and server side. If you know of a tutorial that goes through all of this, that would be awesome, or just a list of tools that make up the cycle… whatever’s clever, Trevor.
I watched a recent video series on youtube by Maximilian, and it covered some techniques for Google Cloud Storage, but most of those were outdated. Something kind of like that?