I'm trying to file as an independent contractor and I'm confused on how to do it. In 2018 I only made $4,000 as an independent contractor, how do I file this amount?

Money you made as an independent contractor would be reported under self employment income.  On the left hand navigation bar click on Income and choose Self Employment.  In the pages for self employment you would record both the income you earned as an independent contractor and the expenses you incurred as an independent contractor.  The difference would be your net Self Employment income.