It is asking me if I had any expenses and I say YES, but it is only letting me choose upgrade to premium or say I don't have expenses. How can I enter them by myself?

If you are self-employed and have income and expenses to be reported on a tax return then you need to use Schedule C for sole proprietors/independent contractors.  When using the TurboTax online editions you will need to upgrade to the Premium edition for the Schedule C.

Sorry,   You can enter 1099NEC or cash Self Employment Income into Online Deluxe  but if you have any expenses you will have to upgrade to the Premium version.

Where to enter expenses in the Online Premium version

https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/enter-self-employment-business-expenses-like-home/L1k6HJY4A_US_en_US