Neither FL nor TX have a state income tax--so not sure what your concern is in regard to whether you are a "FL resident." You will not have a state income tx return to think about for FL or TX. You will need to prepare a part-year return for IL since you say you will spend part of the year in IL and will have income while living in IL. When you prepare your 2024 federal and state tax returns you will need to use the mailing address that you want the IRS and/or state to use if they need to send you a letter or a check.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**