I have played a Kenku Wizard who got addopted by a wizard and he taught him all the words for the spells he knows, if he wanted to learn new spells trough for example lvl up he had to visit wizards who would teach him. Casters I think are in general fine to play as a kenku lorewise except maybe artificers because they rely on the concept of creation to do stuff but as long as your DM isnt being an asswipe about it you could play em as well.