The key to this puzzle is the past
You don't need another hint...
3 Keys are NOT on keyboard. They lead to a single key on the keyboard. Also note that everything is involved in the answer, I don't do red herrings
I'm tempted to say:
First look in the edit history for the complete puzzle because 'The key to this puzzle is in the past', I had help from @Moose's answer and @Joe's comment! Then, from the noticeboard, ski sounds like 'S key' and the note is a middle C. If the map can be interpreted as E.. then in order the keys spell out ESC. This could also match the poem line ending 'and ever be free' or escape.
Shout out to @kayzeroshort:
As commented: "you can get the 'E' from the map by taking the nth letter of each map feature, where n is the given number. (4 - rivEr, 4 - lanE, 2 - sEcondary road)"
I wouldn't bet my life on it though!
Maybe I should have! I actually thought I was wrong because of the hint.. technically they aren't on the keyboard (they're on the noticeboard), but their interpretations E, S and C certainly are!
Very much a work in progress:
I noticed the puzzle had been edited, so I clicked to look at the edit history. Looking at "the past" edits, you can find a real puzzle.
Once you go there:
The noticeboard has a topographical map, which I don't yet understand. But then it has the word "SKI" and middle C.
To open this door you’ll need a key,
If you want to enter and ever be free,
This key is special, its hard to find,
If your puzzled now, then use your mind
Below is a keyboard, a key you must press,
Get it wrong and you die, so do not guess!
Find the correct one by finding 3 other keys,
Here’s a test of your puzzling expertise
My guess at (one of) the three keys:
It would make sense for each image on the noticeboard to lead to one of the keys, so here is my attempt at deciphering that:
The map: unknown
The word "SKI": unknown
The whole note "C": this is actually middle c, the key on a piano which is closest to the middle. However, the row of keys on a piano is called the keyboard, so this may be trying to lead us that the key to press is towards the middle of our keyboard.