Where do i mail my federal return and a check for 2017? I just finished doing them now, in 2019. I am in CA.

In the TT documents included  with the return there should be filing instructions telling you  where to mail returns - enclose checks with them.    make sure you SSN, tax year, name and address are on checks.  

Go to this IRS website for where to mail a federal tax return by state, select the form 1040 with a payment - https://www.irs.gov/filing/where-to-file-paper-tax-returns-with-or-without-a-payment