All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
First of all, all perfect praise be to Allaah, Who guided you to Islam and we ask Him to make you firm and steadfast on His Religion until the day you meet Him.
With regard to your question about the best Quranic schools in Brunei, then this is something we have no knowledge of because we are in another country and we do not have any knowledge about Quranic schools in Brunei.
However, you may ask the Shaykhs and the Imaams whose religion you trust and who have sound knowledge on the Book of Allaah and the Sunnah of the Prophet and you will find a sufficient answer with them, Allaah willing.
Nevertheless, if by your question you refer to studying abroad, then please refer to Fataawa 92676 and 85561.
Nonetheless, the first requirement which a student of knowledge must have is sincerity to Allaah. He should seek knowledge for the sake of Allaah and intend to get near to Him in order to worship Him with insight. Indeed, the Prophet warned us against seeking knowledge for other purposes than for the sake of Allaah, saying: “If anyone acquires knowledge by which the pleasure of Allaah is sought, but acquires it only to get some worldly benefits, on the Day of Judgement, he will not smell the odour of Paradise (i.e., will not enter it).” [Abu Daawood].
The second thing which a student of knowledge needs is to seek the Help of Allaah and to supplicate Him to make one successful in his mission of seeking knowledge. Lastly, he needs to be patient, hard working and studious, and seek knowledge gradually, starting from the most important to the least important, and from the easiest to the more difficult.