Speakers may or may not be installed if it never had radio. Thats ok, cuz they were cheap and tinny-sounding anyway.
Im pretty sure the speaker wiring will be there,-biggest task will be removing the old door trim panels without breaking the fragile cardboard.
Use a wide flexible scraper, or buy a trim kit that has multiple removal tools like this one:
https://www.amazon.com/Tresalto-Auto-Trim-Removal-Tool/dp/B01L8GHB7O
How-to video here;