It is highly recommended that we learn those du’aas that are mentioned in the Qur’an and Sunnah. Sometimes, especially during occasions like Ramadhaan, some people quote some ‘du’aas’ like: Ramadhaan 1, Du’a 1; Ramadhaan 2, Du’a 2…… such types of du’aas that are found in circulation has no authentic base. And there is no specific du’aa for Ramadhaan on a daily basis! You can make as much of du’aa as possible.
It is prudent, however, to learn those du’aas that come in authentic ahadeeth and if it is not possible to make du’aa in Arabic, at least we can understand the meaning in English and make du’aa in our own languages. One such authentic du’aa is mentioned here.