What is a block etc. - Design

A block is a piece of card that is the shape of what garment you are making so you can draw around it on the fabric.
A pattern is the shape of the garment on paper so you can cut the block from it.
A toile is a smaller version of your garment.
A sample is a practice of what you are going to use on your garment e.g. a pocket.
Yes, certain fabrics are suited to certain garments because they have different characteristics. Such as denim is suited to jeans as it is hard wearing and lycra is suited to leotards as it is stretchy.