This topic isn’t that simple and it’s probably not going to be practical to provide a simple list for something complex. If you can’t answer this question yourself, you probably need to learn more about how web servers work, where your files are located, how to secure those folders and more.
But in a quest to be helpful. Your script exists in a folder. I don’t know where this is, which is what makes it hard to answer. But your script is using a relative path: uploads
Here is the relevant code:
move\_uploaded\_file($file\_tmp,"uploads/".$file\_name);
When you don’t have any characters like slashes, dots, double dots, etc. at the beginning of the path name, it means start in the folder I’m in, look for a folder named “uploads” and put the file there.
So wherever your script lives, there needs to be a folder named uploads and that folder has to be able to be written into by the web server. Without logging in to your server, looking at the folder with the script, looking to see if there is an uploads folder and that it has the write file permissions on it (and our forums are not the place to be teaching server file systems and permissions.
You are going to have to spend the time learning this part of your system if you’re going to be successful with this or partner up with someone who knows server-side processes who can manage your server’s for you.
Rob