It is better to do dua in Arabic language; since the Arabic Duas narrated in Hadith books contain the words of the Prophet (peace be upon him). Supplicating Allah with those words is hopefully more acceptable. If you read the translation of these duas occasionally, then you will gradually understand the meanings of every dua, and thus you will remember the meanings when you will do dua. It is also allowed to do dua in English language, but in case English is not your mother tongue, you might feel difficulty in creating the environment of supplication.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband