First off! Thats awesome 🙂 Secondly, I prefer to use the phrase I want to dedicate or devote myself to the Morrigan, versus “have her as a matron goddess” for a variety of reasons. First off the Morrigan is comprised of several goddesses. Secondly the Matronas are a different set of Celtic Goddesses, and thirdly a lot of polytheists will look at you funny if you use that term because in English, Patron is gender neutral and Matron means something different—so its odd to use the term that way. Some people say you cannot choose your patrons, but I think you can, if you start making offerings to them them most will probably respond and you can move forward. But its easier to avoid the term and the judging that people might give you for using it.
Besides the resource lists I like to share, which you can find below, I like to really actively work with the Morrigan. A few practices I find helpful are making ritual masks and doing shapeshifting rituals, observing crows, immrammic meditations, making art for the Morrigan, making offerings of wines and meads to the Morrigan, treading the mill rituals, learning a martial art (kickboxing), putting crow feathers on my altar, making ritual items dedicated to her, helping women in need, sex magic, and visiting caves and mounds.
And as always, I must mention, I am not a reconstructionalist. I am a witch and of fairy faith and so I use different kinds of source material and evaluate it differently than a reconstructionalist might. If you are in university, or have any friends in university or who work for a university, I suggest asking them for help with the various dissertations.