I'm an amateur historian and I'm trying to study the early Portuguese empire and early Spanish Empire. I've had a lot of trouble finding material on the Portuguese invasion of Ceuta. I know about who participated in the invasion (at least I know who invaded, not very much on the defenders themselves) and the amount of soldiers were used in the invasion. However nothing more than the later attempt to retake it by Sultan Abu Said Uthman III in 1418. Anything more I cant find. I don't own any books on the subject at all, and if you do know books about this please link them or name them as I would be very grateful. Is there any free courses I can take on this topic? I trying to study really hard and my local library nothing but high school textbooks on the subject. Please if you could help me in my endeavor I would be very grateful.
So, one of the main sources for conquest of Ceuta is Cronica de Tomada de Ceuta by Gomes Eannes de Zurara. The original is in (old) Portuguese, but I believe English translated excerpts regarding the conquest itself can be found (online and free) in this work Conquest And Discoveries Of Henry The Navigator Being The Chronicles Of Azurara. Alternatively, this page also translates some paragraphs. But we must make some disclaimers about the source. The original Cronica was written around 1450, so over 30 years after the event by a man who was a young child at the time of actual conquest, and who was at time of writing employed (and very much influenced) by Infante Henrique (prince Henry 'the Navigator') and the work focuses a lot on Henrique and his exploits and we should be careful how much we should take it at face value and how much was it propaganda (the exact role of Henry Navigator has been called into question by several historians in the last few decades, although I am not sure where the opinion leans to now)
For more information on the conquest I recommend a JSTOR article On the Conquest of Ceuta by H. V. Livermore. If your institution does not have access, you can log in through google and read for free.
The other important work is the book Prince Henry "the Navigator": A Life by P. E. Russell, although you might have trouble accessing this one. However it would be really worth your time to get it as the chapters about Ceuta are highly detailed and full of all possible information.
Both of those works (especially Russel's work) move away from the Cronica and contextualize the events with other sources and contemporary events, in both Portuguese and African settings.
Lastly, pretty much any work relating to Portuguese history will give at least some mention and description of conquest of Ceuta, as it is considered a pivotal moment in beginning of Portuguese expansion. Whatever you can find will be good, but I can recommend: