Maybe. There were a few grammatical errors.
So the trigger works, but it says the text is empty. I tried Unicode, ANSI, and UTF-8 encodings. Nothing works.
function firststepsF1(heroname)
MessageBoxForPlayers(GetPlayerFilter(GetCurrentPlayer()),GetMapDataPath().."firststeps1.txt");
Trigger(REGION_ENTER_AND_STOP_TRIGGER, "firststeps1", nil);
end;
Trigger(REGION_ENTER_AND_STOP_TRIGGER, "firststeps1", "firststepsF1")

готовность 70% PAUSED