I do have a deadline
Hopefully is sometime next June...
am working on a project that will use force sensors (placed in a floor mat) to trigger an audio file (mp3 or wav-whichever is best supported).
What is going to play the wav or mp3 file? Not the Arduino. You need a shield.
There will be several sensors and several files.
Fine. No problem.
I wonder if I can do this by modifying the blink LED with a push button( or light sensor) sketch?
Good idea. Just remove everything before setup(), everything between the curly braces that delimit the setup() function, and everything between the curly braces that delimit the loop() function. Then add a little new code.
Is it possible to have this trigger a file to be loaded
Yes. First, define the circumstances that cause a file to be loaded, then define the circumstances that defines which file is to be loaded, then define where the file is to be loaded from.
or will I have to write the program in Processing?
No. The Arduino can't run Processing sketches.
I have been working on a sketch in Processing that uses a keyPressed() to load a a wav and/or mp3 file using the minim library but have been having many difficulties.
I am wondering if I am approaching this correctly
So am I. It's hard to tell from your code.
and could really use some advice on where to start...
OK. You only need one punctuation mark at the end of a sentence.