I downloaded from GOG but no way can I see how to launch it. It seems it has to be configured in some way
I had no trouble with Tomb Raider 1 from GOG, which uses DOSBox.
The other Tomb Raider games are Windows 95/98 games and can't use DOSBox, so those are more likely to have conflicts.
Did you get an icon on your desktop when you installed the game?
What "configuring" is the game expecting you to do?