Hi Wayne,
Like Greengolfer15 in the UK, I am not from Laminar Research either. Just a flight simmer from downunder.
Your opening sentence in your posted question initially confused me into thinking you are referring to Microsoft Flight Simulator X Gold Edition. I have that edition as well.
In reading further I gather you have downloaded the demo version of X-Plane 11. The demo version is limited to a trial period of 10 minutes once you have selected your aircraft (in your case the Cessna 172) just to "get the feel" of X-Plane. You are restricted to one airport, namely Seattle (KSEA) in daylight. I understand you will not be able to trial other benefits (VR) that are available with the full version. Once you officially purchase the software you apply the supplied product key and all will be revealed.
To assist further in solving your problem you should supply more specific details of your system instead of the scant details in your last sentence in the comment you attached below your original question. Because you mention you are running a Pentium CPU suggests to me your system may not be able to run X-Plane. Have a look at the following link found at https://www.x-plane.com/kb/x-plane-11-system-requirements/ regarding system requirements.
To provide further assistance in providing a possible solution please attach a copy of your log.txt file to the comment you have previously made after your original question. This file is not to be confused with the X-Plane Installer Log.txt file. To attach the file start by editing your comment and follow the advice given in the following link found at https://questions.x-plane.com/?qa=blob&qa_blobid=17830136656522860642
The more details you provide regarding your problem(s) raised in this forum the better chance of getting assistance.
Greengolfer15 and myself look forward to reading the additional information.
Regards
Glenn