@Brandon ***********
yes this is exactly correct. If you were not married when the child was born you must use the Thai court system to become the recognized father legally in Thailand.
As for owning land this may actually be possible depending on the law, which I am not an expert in. Consult with a good attorney and this might be possible. You can probably gift the child money, and if you are a legal guardian of his estate then perhaps you can buy land for him? I don't know it's an interesting question actually I'd love to know more.