Going by the Great Book of Music of Al-Farabi there would have been oud, psalteries ( somewhat like the present qanun), harps, drums, racks of bells, flutes- and singing, of course. The oud would make a great impression on Europeans, who would adopt it and call it the lute.

Guitar is actually an anti-lute. The Spanish noted the Arab/Persian origins of the lute, and being intolerant of Islamic things created a guitar-waisted instrument with a similar tuning, which they called a vihuela. That later became the guitar.

Just to note, I can answer this question, OP, but I'm currently travelling so my resources are somewhat limited compared to what I'd normally be able to post (all my books are several thousand kilometres away!)

So music history and theory is outside the realm of my expertise, but I can answer you specifically and give you some people to read about.

A famous musician of al-Andalus known as Ziryab is a pretty good starting point if you're looking to learn about Andalusi music. While not Andalusi himself - we don't know his origin for sure but I'd suggest that he was most likely an arab, or perhaps from northern africa, based on what I know about him - Ziryab was one of the 'founding fathers' of the genre of classical Andalusian music that is popular throughout Morocco, Libya, and some other places.

Ziryab came from the Abbasid Caliphate and served the Caliph al-Mahdi, and went to al-Andalus in 821 where he began his famous career in the court of Abdul Rahman II. He spent most of his life there, had a music school built and ran it, training his children and others. Ziryab is particularly known for his playing of the 'ud, a lute-like instrument that was known and popular both in al-Andalus and the middle east. He brought with him music ideas and sounds from Baghdad and added to them by changing the instrument itself; I've seen Ziryab credited with the addition of extra strings to the 'ud (his 'ud had, if I remember correctly, five strings rather than four), as well as for having personal flourishes that were appreciated by Andalusis such as his playing of the 'ud with feathers of local birds.

I've seen it said that the 'ud was the first truly popular stringed instrument of Iberia (not necessarily the very first, but the first that made a marked cultural impact). I could be wrong on this however as, again, I'm no music historian, but this is the impression I've gotten, especially from what I know of Ziryab who is known to have altered it. The 'ud was definitely popular by the time of early 11th century, and had a range of sounds and traditions associated with it that were well established by that point. It spread to France and much of Europe and this was part of the Cordoban Caliphate's status as a cultural centre of Europe during that period.

As for other instruments, drums were very popular, as was something now called a 'rebab', an instrument that I think is also common in other parts of the world but is still widely used in Andalusian classical music today. The variety played in Andalusian music though is a bit different to the ones that I think you find elsewhere. We also know that Ziryab was fond of tambourines and used them to help teach his students poetic meter and rhythm, as well as a range of other music concepts and ideas (which I can't explain adequately as music theory is a bit outside my knowledge).

Hopefully that helps a bit; I would've given a more in-depth reply but again, my resources are somewhat limited at the moment.