The mujahidin were not al-Qaeda. There were seven (Sunni) mujahidin groups based in Peshawar which were authorized to receive American funding via the ISI. A small number of Arab volunteers traveled to Peshawar during the war to join up with them, although only one of the seven mujahidin commanders (Abdul Rasul Sayyaf) was actually enthusiastic about receiving them, and he was one of the least powerful of them. Elsewhere Jalaluddin Haqqani also happily received some.
Al Qaeda was not formed until the very end of the Soviet War, partly due to bin Laden’s frustration that the Arab volunteers were essentially being ignored by the mujahidin. A small cadre of Arab fighters led by bin Laden set up a tiny ramshackle camp just inside the Afghan border and blundered into maybe three genuine skirmishes. Many if not most Arab volunteers for the mujahidin did not join al Qaeda, and there was at least one other independent Arab training camp set up close to Haqqani (and others such as al-Zarqawi’s would emerge long after the Soviets left).
So while some Arab volunteers undoubtedly got their hands on weaponry provided by US funds, they did so before Al Qaeda was even a thing, and in any case their contribution to the war was negligible.
I know many will roll their eyes and say these details are unimportant, but fudging the lines between the mujahidin, the Taliban, and al-Qaeda is exactly how you end up with innocent men spending years in Guantanamo.
I really recommend reading
The Caravan by Thomas Hegghammer on all this.