If you received income as a consultant for a company, you'll first need to know if that company is issuing you a T4A for the income earned. If you do receive a T4A, you will enter this first in TurboTax in the T-slip section and the income will carry over to a T2125 - Statment of Business Activities form where you can "edit" and add further information in regards to the self-employed income.
If you have not received a T4A, you will need to enter the income in this same section. Gather any invoices or other proof of income earned and any deductions for expenses incurred in regards to this.
Then select from the sidebar in TurboTax Income > Self-Employment > Self Employment Intro and continue through to make your entries.
Here's a helpful video from TurboTax that explains how to report Self-Employment income: How to File Taxes for Self-Employed or Home Businesses