Sorry--with online TurboTax -- which is what you are posting from, if you need a schedule C then you must upgrade to Self-Employed. The schedule C is not available for Deluxe or Premier. If you were using desktop software the answer would be different.
You can enter Self Employment Income into Online Deluxe or Premier but if you have any expenses you will have to upgrade to the Self Employed version.
Or there is TheTurbo Tax Freedom website which is free for federal and state if you qualify. And has more forms than the Federal Free Edition, like the full 1040 return and Schedules A, B, C , D, E, F, EIC, H, K-1, SE, etc.
NOTE: You will have to log out of your regular Turbo Tax Account and setup a new account with a new username and new password or it will take you back to regular Turbo Tax.
To qualify for the Tax Freedom website you just need to meet one of these 3 things
AGI $34,000 or less
Active duty military with AGI of $66,000 or less
OR qualify for EIC (earned income credit)
In order to use the Tax Freedom Edition, you have to start it at a special website: