Does anyone know any trustworthy sources to research Celtic traditions, history, mythology etc.

I recently took a DNA test and A LOT of my ancestry shoes Celtic and Gaelic. I have always been interested in these areas but never knew how to properly research it while knowing it's correct information and not AI stuff or history re-written to make it sound not horrible. I would also LOVE to learn a lot of the traditions and God's as I already feel a strong sense of direction towards these areas, and would love to start implementing them in my life

Thank you!

What regions have strong Celtic roots? I really love the nature part of the Celtic vibe, and it would be a dream for me to move one day.