Which language is easier to learn, Spanish or German?
Choose German because among FARANG many more native German speakers come to Thailand, and live in Thailand, than native Spanish speakers, so there will be many more opportunities for you to interpret, help out, and communicate in general with FARANG. The best thing for you to do, however, is focus as much as possible on English because most Germans can speak English, and with good English MANY doors may open for you in your future, even if you never leave Thailand.