Saving and Retrieving the ID of the Uploaded Image from MySQL

[Kariot]

Hello, I decided to set up a project on a domain I purchased to get started with PHP and MySQL. I have created a panel by carefully studying and learning about it, allowing me to add content and place it wherever I want, and so on. However, for the project I have in mind, I also need to use images like 300x300. I tried to work on this, but my knowledge hit a wall here. From what I can see, there is no need to bloat the database with images. Instead, when uploading the image to the site, it should be uploaded with a unique name and that name should be used when retrieving it. However, I have no idea how to do this. I managed to bring it by using simple PHP codes, but I got stuck here. How can I upload an image? How can I ensure that the name of the uploaded image is unique?