In the garage, as in the apartment
The type of wall decoration inside the garage depends largely on the wall material. If these are building blocks, the walls are most often plastered. Some do not pay much attention to beauty and leave it as it is. But in the case of some blocks, it is better to plaster them (non-autoclaved cellular concrete, for example, or shell rock with limestone) to protect it from excessive moisture. Plaster - the best of finishes
Frame garages are often sheathed inside with plywood. If the garage will have constant heating, you can use any, if it is heated occasionally, or not at all - then you need moisture resistant. You can make the trim with any sheet material - GCR.