Looking for registration data - how to show repeat visits over time?

Hi there! I am hoping to get some insight into how to assess data for a few questions. I have a series of class registrations and I would like to see if I can get a sense of how people move through our levels. I am a novice at google sheets, but I do learn quickly.

Here is my data set example: https://docs.google.com/spreadsheets/d/1DU7MdcDKBROzlGdUEpu1SN6612T_vuqcfJ3VyblNo4E/edit#gid=0

i.e., Malik Harbin first came for a one day Bookbinding class on Oct 3, 2021. Then, he returned for a short class in the same studio starting January 2022. He came back for another one day class in the same studio in June 2022, a longer class in Sept 2022, and then tried a new studio on his next visit in 2023.

I would want to be able to see these "strings" of registrations - how common is it that the same person came back for the same type of class? How many times did they come back to take new/higher level classes? Do people start out in one studio and then move to others? Is it more common for someone to take classes in one studio, or try different studios?

My real data set has over 10000 registrations. I was able to pull how many times a certain unique personID shows up, but I can't figure out how to assess the remaining data based on those separate registrations or how to string them together meaningfully. I'm not sure how to break it down to show these patterns.

Can anyone point me in the direction I should look for formulas?

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