I would like to know why I have not received my 2018 tax returns. I also need to change my address. How do I go about doing this?

[VolvoGirl]

When did you file?  Was your return Accepted? You can check your efile status here
https://turbotax.intuit.com/tax-tools/efile-status-lookup/

When you efile you get back 2 emails. The first email only confirms the transmission. The second email says if the IRS (or state) Accepted or Rejected your efile.

Then only the IRS can tell you. IRS Where's my refund https://www.irs.gov/refunds/
Make sure you are using the refund amount from your actual federal tax return and not the combined amount Turbo Tax showed you at the end. That was for federal and state combined.

When you log into your account you should also see the status and if it was Accepted or Rejected, Started, Printed, Ready to Mail, etc.  what does it say?

[VolvoGirl]

If you already filed your return and it was accepted you can not change the address. If it rejects you can change it and resubmit it.

If you change your address after filing your return, you should notify the post office that services your old address. Because not all post offices forward government checks, notifying the post office that services your old address ensures that your mail will be forwarded, but not necessarily your refund check. To change your address with the IRS, you may complete a Form 8822 Change of Address, and send it to the address shown on the form.

How to notify the IRS of an Address Change….
http://www.irs.gov/taxtopics/tc157.html

Here is a blank form 8822……
http://www.irs.gov/pub/irs-pdf/f8822.pdf