I don't believe you can edit the "Getting Started" display, but it's possible to configure your client to display a different web site entirely. For example, you can display a page from your corporate intranet. The information about how to do it is available on the GTAC site; search for "myTeamCenterApp.URL".
Alternatively, you could look into using the LaunchPad perspective, which is hidden by default.
I already have a .html file ready. I would like this page to start with Teamcenter, rather than "Getting Started".
Which file or variable should I configure for this to work?
For each client, in the "customer.properties" file located in the %TC_ROOT%/portal/plugins/configuration_*version* directory. Add a line "myTeamCenterApp.URL=file://(location of your htm file)"
If you do not have a customer.properties file in that directory I believe you can create it.
I recommend putting your htm file in a shared location where all clients can have a clear path pointed to it.
I am unware if this can be done at a site level or of any alternative methods.
NX 11 | SW 2016 | Creo 4 | TcUA 11.4
Evaluating: AW 3.4