As you are a novice in calligraphy, I suggest you find a time to visit the "Calligraphy Street" in Wende Road, Guangzhou, take the subway and get off at Agricultural College Station, or get off at gongyuanqian station on Line 2. After you go, you will certainly gain a lot. In addition to antique calligraphy and painting, there are Four Treasures of the Study, where you can buy or engrave calligraphy seals.
Generally speaking, calligraphy seals are made of stone, but they can also be carved with other materials. There are dozens or hundreds of blank stone prints, Qingtian stone is cheaper, Shoushan stone is more expensive, and the lettering varies from tens to thousands of dollars by word or by individual, depending on the reputation of the sculptor.