'Can you please help me with my Eclipse build error

I have made a basic Android App for my studies in Eclipse 2020-12 (lines up with the study module).

Now I want to run my app in the emulator to test it, but when I click on Run (the green little arrow), I get the error below. How do I fix it?

I followed these steps to install and setup my Eclipse:

I have the following installed:

JRE 1.8.0, jdk-7u80-windows-x64, eclipse2020-12-inst-jre-win64, Java 8, Android SDK

Keep in mind, I am new to all of this so you will have to give me Android for Dummies step by step instructions, lol.

Edit:

eclipse

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