You can proceed this way to find the correct path.
<a href="{{ base_path() . "/public/storage/app/public/upload/".$user1->upload}}>
From documentation: The base_path function returns the fully qualified path to the project root.
Link: https://laravel.com/docs/5.4/helpers#method-base-path
You could also use
public_path()
Then it would look like this:
<a href="{{ public_path() . "/storage/app/public/upload/".$user1->upload}}>
The public_path function returns the fully qualified path to the public directory.
However, if you followed the instructions from here: https://laravel.com/docs/5.4/filesystem
you can load it in this way:
<a href="{{ asset("storage/app/public/upload/".$user1->upload) }}>
Hope this helps