Well as most have indicated the adjustment screw simply reduces/increases the travel of the trigger before it trips the hammer and lets it fall.
It has no effect on weight of the trigger pull to my knowledge.
There are a few schools of thought on adjusting this, many say let a gunsmith adjust it, to each their own and gunsmiths must make a living like the rest of us.
I think it is generally agreed that find a allen wrench that fits the screw, cock the hammer, screw in the screw about a full turn, pull the hammer and see if it drops?
IF so then continue to screw it in about 1/2 turn and try the hammer after each 1/2 turn, once the hammer locks and will NOT drop when you pull the trigger, then you will need to back the screw out at least a 1/2 turn, just depends but I normally back mine out a full turn to be safe, after all you don't want to end up with a carry gun that if you pull the trigger it will not fire.
Actually I am a lot more interested in the trigger reset than the first shot of trigger travel, but what ever you do make darned sure its 120% reliable as to dropping the hammer when the tigger is pulled.
Hope this helps and if I made boo-boo someone jump in and correct it.
Welcome to the forum as well, enjoy your 1911.