I can try to explain SassiX’s solution a little simpler. Let’s take this one event at a time. Since you seem to be new to scripting, we can help you learn some basics that should speed up your workflow.
Firstly.
https://i.imgur.com/iH90rqK.png
This wonderful thing is what I like to call a comparator (think minecraft). It take’s two inputs and decides if A is equal to B or not. (I believe this works Visa Versa as well). You can get to it be Right Clicking anywhere in your Blueprint editor and typing “==” into the search bar. OR, you can drag off any boolean (red) pin from a node that has it and type “==” as well.
Second, the reason why your Audio file pin and the Play pin are not connecting, is because they are of different types. Like SassiX said, you have a Media Player component. You want the Audio Component. A quick and ez fix for this is just simply click and drag from the pin on the new variable you made and in its search box, type: “Play”.
This is a good habit to get into , as unreal has a lot of context sensitive functions, and providing the context (dragging from a pin/variable/etc) before you look for a function will help you save plenty of time in the long run.