I'm doing shadow maps starting with directional lights thinking it would be simpler, untill I realised I have no idea how the actual view and perspective matrices are computed, since all I have is the light direction.

Judging from what Ive found it seems I need an orthographic perspective matrix yet I havnt found a good explanation on what it actually is and how it is constructed using for example glm::ortho.

And the view matrix itself is puzzling.

Any pointers?

You will need to learn the math behind the matrices, i recommend the book called "Interactive Computer Graphics - a top down approach" This book gives you the solid math you need to deal with the matrices( it also shows you how to deal with shadows

The projection matrix I can understand, but what of the view matrix?