I do kind of wonder how much of that code is copy&paste which is no problem but coupled with your question versus the ones you should be asking I'm not sure what advice to give but I am pretty sure that just fixing that code will not help you learn anything useful.
Your variables and your use of them have issues. Sure you'll get values out but not correct ones.
Analog read returns an int 0 to 1023. Dividing buffer by 1024.0 is one error. Divide by 1023.0 to get the proper range. 1024 while "intuitive" is wrong. Don't feel so bad, I did that too.
When you mix variable types and don't want the compiler to screw it up, use casts like this:
int myRead = 234;
float myResult, myScale = 10.9;
myResult = (float) myRead / myScale;
The (float) makes sure that myRead is cast into a float for the division and myScale is not made into an int.
Serial.println( myResult ) adds a newline after the number is printed where
Serial.print( myResult ) does not which would let me add more text with a print on the next line.
Serial.print("Resistance Value: ");
should show you how to print 2 things on the same line so really, how hard can adding 1 more be?
And that's why "I do kind of wonder how much of that code is copy&paste."
Copying code is NOT a problem unless you don't understand what you copied.
Do you need some links into the Arduino site where the basics are explained, the standard commands/functions are referenced, the examples included in your IDE are gone over and such? Because really, you need more background just to save yourself time getting up to speed. Just poking at what you mainly don't know how to read is not going to help much.
You need to refer to references for every command/function in the code that you are not SOLID with. You want nothing in there you don't know about doing you don't know what. Look things up, the machine won't "know what you really mean".