so I am actually trying to get into software development and I currently have just spent a few days making a GUI in Photoshop. Now I know how to code in Java and Python but I have never implemented a GUI before. I am stuck on this because I know I can write the code and everything but how do I take what I made in Photoshop add some java or python code to it to make certain things happen? I have zero experience in this and I have only written code to accomplish tasks without the need for a GUI.
but how do I take what I made in Photoshop add some java or python code to it to make certain things happen

No, you cannot expect things to happen magically, for that you need to learn front-end technologies like HTML, CSS, JavaScript etc and manually convert the UI which is in Photoshop to corresponding code. This applies for web applications.
If you want to build desktop application, you need to use Swings, SWT etc to achieve the same.

I have zero experience in this

If this is the case, I recommend to read some basic tutorials, then you will get idea what to do
UI Designed in Photoshop for Software