In the membership-area of karate-selfdefence.com you can find -between much, much more content- a 9-week-course about working on your spirit in terms of contemplation, awareness etc. It is mainly made for internal preparation for self defence szenarios, but the side effects are for sure that you are entering a more mindful life with these practices.
However, if you want to engage deeper into your internal work and follow a spiritual purpose, there are two teachers, I want to recommend (both offer online classes):
1. Sensei Sydney Leijenhorst, 6th dan IOGKF and chiefinstructor of the Netherlands, offers White Crane Qigong (very related moving principles to White Crane Kung Fu, which Goju-Ryu is strongly influenced by), meditation, Karate and much more. His teachings, inspirations and function as a role model have a very big impact on my development since over 20 years.
2. Tiana Tefy is also a very skilled qigong- and meditation teacher. She offers many different forms of retreats and online-retreats, regular classes and so on. When you contact her, you know you are in very good hands. We shared our path for a while, already then she was a very skilled and highly progressed on the internal way.