كلاهما مهم Both are important. But I think learning writing first is much easier because of there are many learning materials starting with reading and writing. I don't sure if you can learn speaking first, it's not easy, except you learn a dialect informal language, and it's really not good way at all.

By speaking first. But before this you need to learn the letters.

لتعلم اللغة العربية يجب إتقان الكتابة أولا أو الكلام أفضل لِتَعَلُمِ الْلُغَةَ الْعَرَبِيَةَ يَجِبُ إِتْقَانُ الْكِتَابَةَ أَوَلًا أَوْ الْكَلَامُ أَفْضَلُ

مرحباً .. حاولي التواصل معَ أصدقاء منَ الموقع حتى تتمكني من تعلم اللغة العربية عبرَهم :D