That is what everyone has used for decades.
I would drill & use wood screws if decor or screws/plastic anchors if going thru stucco. Or just drill handle end to hang for use or just lay over rafters if long enough. if not throw some boards up there for overhead storage or place in canoe & just store that up there.
There are many ways in which one can purchase a garage building. Most garage building are built within a house or complex and are purchased from house builders. However, unattached garages can be bought from garage salesman.
Garage
In the U.S. it would be a garage.
It was Jobs and Wozniak creating circut boards in a garage.
You do not need a building permit if changing the interior of the garage. If you are using heavy machine equipment and moving large lumber on the outside of the garage to make changes then a building permit is required.
Depending on where the garage is to be constructed, building permits may be required. There may be zoning restrictions about the use of the garage, the footprint of the garage, the materials, design, etc. The planning phase must include all of these considerations.
A parking "building" is similar to a parking garage, in which a number of floors are connected by ramps which can be driven on in an automobile to find parking. the difference between a garage and a building is that a building is generally completely closed in on most floors.
It will vary depending on where you are but generally if the garage is not attached to the home, you do not have to sheet rock it.
The noun 'garage' is a singular, common, concrete noun; a word for a building used to shelter or repair motor vehicles; a word for a thing.The word 'garage' is also a verb: garage, garages, garaging, garaged.
A metal storage building could suffices as a garage if it is kept up but it is definitely not the best option. I would suggest going ahead and getting a real garage built.
There are a number of places that one can find blue prints for building a garage on the internet. Some sites you may be interested in include The Garage Plan Shop and Sketch 2 Plan.