All my scripts stopped working when closed and opened project. Solution?

I am following a tutorial for fun, am not at all programing savy. I did every single thing the tutorial said, the only difference was that I stopped for the day and in the morning when I openned the project to continue all my code wasn’t working. I noticed only when I needed to open a script I had already done and when apllying to an object it gave me this notice:
8188140--1067037--upload_2022-6-7_18-52-33.png

Then i realized nothing was working and all my scripts give the same message.

I searched forums with similar problems but couldn’t find a solution. Hoping someone can help me here. Thanks!

Am using 2018.2.8 because it was the closest to the tutorial and I didn’t want to have any issues, thought it was best.

Don’t know if this is a good one, but an example of the code.

With my limited knowlege i really don’t know why it isn’t letting me even apply it to an object, I get no errors in visual studio.

First thing to do is check your console window for any compiler errors. If you see any, you have to fix all of them before proceeding, even if they don’t seem related to this problem.