can I file just my federal taxes

Yes, you can file just your federal tax return.   If you live in a state with a state income tax. you will still need to file a state return, but you do not have to prepare it or file it using TurboTax if you do not want to.  You could use the state's tax site to prepare your state return.

Yes, you can file just your Federal taxes.  Even if you are required to file a state return, it does not have to be completed at the same time as the Federal return.  You can come back to it later, or file it another way.

Take a look at the following TurboTax help article if you're having trouble skipping the state return:

Can I file my federal taxes now and skip my state for later?