what would the steps to cutting a piece of wood 1'x12'x14 be in high school shop class?

Question

1'x12'x14 is only a rough cut the piece needs to be sanded and planed to final thickness

Answer 1

Use your t square to ensure the rough cut end is straight, then mark and cut that end. Measure the final length, use your t square again. Mark and cut that end.
I think you meant one inch by twelve inches by fourteen inches, but that is written 1"x12"x14".

Answer 2

Since you don't mention if this is a "cross cut" or a RIP cut, and we can't know the tools allowed for your use, there may be more than one way to accomplish the task.

A cross cut on a 1 x , can be accomplished easily with a decent hand saw, a square, a pencil to line the cutting edge, and your effort. I'll assume a school shop class may not have a chop saw large enough, but even at that a 1 x 12 would have to be flipped to complete a cut. I also can't know if the shop has or allows a "Skilsaw" for use.

To do a decent RIP cut, a table saw would be best.

In any case at 14 ft. long you might need at least one other to help, or a work table and brace or two or more saw horses.

Steven Wolf