Question: In what language should prayers be said?
Answer: ב"ה Shalom
The best way to pray is in Hebrew, which is "Lashon Hakodesh" the Holy Tongue. When one prays in Hebrew one fulfills their requirement even if not every word is understood. (משנה ברורה סב:ג, קא:יג וספר תפילה כהלכתה עמ' צה))
Today there are many prayer books with proper translation in to English and other languages so that one can glance at the translation until he becomes more knowledgeable of the prayers.
If there other details you want to ask about prayer, please specify. All the best