What does "every year starts from ten thousand" in the calligraphy signature mean?

I don’t know what the content of the work you see is. Sometimes the signature will change based on the content.

There are several common signatures. For example, this year is the year of Jiawu, and it is the sixth month of the Gregorian calendar and the fifth month of the lunar calendar. Then it will usually include "such and such book in the early summer of Jiawu", "such and such book in the early summer of Jiawu" "So-and-so book", "Jiawu Xia so-and-so book" and so on. Sometimes they also add the name of their usual place of residence, such as "So-and-so book in so-and-so book" and so on. I wonder if I can help solve your problem.