For a visual novel-ish vibe

How do i create the effect of the text box fading in and the text being typed and then it fading out when the player presses a letter/number to progress?
As far as the text being typed, you can use string_copy(). You create a variable that tracks how many characters in your typewriter effect is, and increase it by n every step. Then you use string_copy to take everything from the first character (1) to the current typing position:
var _modifiedString = string_copy(inputString, 1, typingPosition);

draw_text(x, y, _modifiedString);