Question

Fla Requesting F-1120 for my llc. Had no sales or income. Had costs with setting it up do I need to redo my 2020 taxes?

No text available

If you have a C corporation in Florida you're required to file a federal and state return even if the corporation had no income.

Employee

I agree with @Critter-3.

Further:

A limited liability company (LLC) classified as a corporation for Florida and federal income tax purposes is subject to the Florida Income Tax Code and must file a Florida corporate income/franchise tax return.
An LLC classified as a partnership for Florida and federal income tax purposes must file a Florida Partnership Information Return if one or more of its owners is a corporation. In addition, the corporate owner of an LLC classified as a partnership for Florida and federal income tax purposes must file a Florida corporate income/franchise tax return.