Online has not opened for 2019 yet.  Come back in December. Or you can buy the Desktop CD/Download program now at https://turbotax.intuit.com/personal-taxes/cd-download/ 

And you will be filing a 2019 return that is due in April 2020.  You should wait until you get all your tax forms like W2 and any 1099 forms after the year ends in January.  The IRS won't start taking returns until late January or February.  

The Online software is transitioning to the 2019 software this month.  2018 is the one that was just completed, and some users procrastinated, so some instructions are still in there on how to finish off their 2018 taxes

The 2019 software will "start" to become available in December 2019, to be filed Jan/Feb-April of 2020.  (But the earliest releases will be pretty sketchy until all the tax forms are finalized in ~Jan-Feb of 2020)

Beyond that, you need to be clear as to what tax year you are talking about...the tax software is labelled according to what tax year it is used for.  2019 tax software is for 1 Jan 2019 to 31 Dec 2019 and prepared and filed in the first 4 months of 2020. 

 So if you are not a dependent for 2019, then 2019 taxes (filed in 2020) will be the first year you file as not being a dependent.  or...if it truly is next year that you won't be a dependent, then you don't have to worry about dealing with that until Feb-April of 2021  (other than making sure your job tax withholding is set right for 2020 wages)