Currently at the 'Colorado Portion of Other Income step, it's asking about a Form 1040 Schedule 1, idk what that is, I only had one income source and it's on my w2.

Form 1040 Schedule 1 is part of your federal return that Turbo Tax has created for you  In Turbo Tax, click on View, Forms.  You will see Schedule 1 right after your Form 1040.  Schedule 1 is "Additional Income and Adjustments to Income:"