OK I got my timer for putting up the poster set up. On interact the game sets a variable to 45 and I created a loop that first checks that the variable is > 0 and if it is it checks if the player is pressing the interact key and if they are it subtracts 1 from that variable and waits a frame. If they aren't they get a message telling them to hold it for longer. If the variable reaches zero it puts the poster up like normal. Solving problems is fun.
Now I need to find a way to display progress for it.