Hi Patrick,
Thank you for posting your question in this community.
Based on your description about “the first line has my name in bold”, it seems that you are referring to the Insert Notes feature in Excel (formerly called "comments" in earlier versions of Excel)
For your information:
The difference between threaded comments and notes
If you would like to remove you name, there is a feature can remove it. But, you can try out the following workaround to “hide” it.
1: Go to File > Option > General > Under Personalize your copy of Microsoft Office.
2: Remove the text User name and check the option “Always user these values regardless of sign in to Office.
3: After you remove the text in “User name”, you will still notice that Excel note will input your Windows user name as default, because this field cannot be left as blank.
4: In this scenario, you can enter a “Space” into User Name
As the result, there will ne no name inserted in the notes.
Note: it only effects with the new workbook and notes you inserted.
To change the default font in notes. Based on my search and test, I am afraid that we can only change the default font size not the font in Windows 10 for note/comment according to this article about Format worksheet comments: Change default font for comments in Windows 10.
Based on my findings and tests, I am afraid with the built-in feature of Excel, it is not feasible at this moment. Unlike Windows 7, we can custom the font for Tooltips in Display settings. Some users also noticed this limitation in Excel and raised an similar idea about Default setting of excel comment (Font & size) doesn't change. Changing it every time is hectic. In Excel User Voice. If it is convenient, I suggest you can vote and subscribe this idea. As more and more people vote on this idea, it can let the related team be aware of this limitation and improve it in the future. Sorry for the inconvenience caused.
Best regards,
Dihao