Start with the first course to learn the basics and terminology. Then each other course can be done independently. There are lots to choose from and more coming. For instance the Diaphragm Mastery:

Was asked to teach at a new local jiujitsu gym that opened 5 minutes from my house. Soft roll out, 1 student here, 3 there in September. This monday I had 12 students on the mat. So exciting to be part of something new that I am passionate about. It drives me to think of new ways to become my better self.https://sonomavalleyjiujitsu.com/home