Old portuguese/galego were spoken in the northwestern part of the península, as they were conquering down the península what languages would they have encontoured? latim based ones and arabic based ones? beber ones? others? And were the languages separated by geography or by peoples? So moors would speak something, christians another and jews a different one for example.
I want to start out by pointing you to this comment I made that explains why "moors" is not a preferred term nowadays, and gives some detail as to the diversity of al-Andalus ethnically. It's a non-descriptive, generic term that misrepresents the character & culture of people that lived in al-Andalus, and is outdated.
I also discussed cultural & linguistic differences among people of al-Andalus in this comment.
I think these two answers should give you a better understanding of cultural & linguistic differences in Iberia and al-Andalus especially. Language divides and differences are explained in the sort of overall terms you're looking for. As you'll note from the second post I linked, by the time of the 10th century a common Andalusi identity had emerged. Language differences in that period were primarily not cultural or religious in nature, but mainly determined by one's proximity to an urban centre. And i the 10th century most people in al-Andalus were bilingual. In very general terms, this meant that more rural communities were more likely to use Romance as their main language and Arabic when needed, and the reverse in more urban regions. Of course, by the 10th century writing specifically was generally in Arabic, even among Christians.
According to Roger Wright (a language historian who focuses mainly on Latin in Iberia) the fact of widespread bilingualism with Arabic and Romance was most likely the case as early as the 8th century. This is because, Wright notes - something that I can corroborate from a variety of other sources - many of the Arab, Berber, and other settlers that arrived had mothers who born in Iberia. This meant that Romance was a widespread language regardless of religion or culture. This was true of the Jewish community in al-Andalus as well, who were bilingual Arabic-Romance speakers since Hebrew there was only really used at the time as a liturgical and written language. So neither religion nor culture in tenth century al-Andalus were really significant dividers in terms of religion.
The main divide though was between the far northern kingdoms that were mainly Romance-Latin bilingual, and al-Andalus which was Arabic-Romance bilingual.
Let me know if you have any followups.