Since the undead are magical beings and this is a sort-of low fantasy RPG, can characters beyond undead ones have magic abilities? If so, to what extent?

Let's say that I want to RP as an experienced but still common trooper. Will that soldier have any knowledge of magic to, say, enhance their armor? Or is magic less widespread? If I want to play as a famed, powerful knight, will that character have magic abilities instead? Do mages/witches exist? Speaking of "new faiths", will there be priests with magic abilities?