Prefilling Form for Adobe Sign and making prefill the default option instead of "anyone"

I have a form I use in Adobe Acrobat that I require clients to sign.

I have formatted this form with mathematical functions so I can't use adobe sign as my template form (functions don't work).

This form has several form fields that I fill in before sending it to the client to sign.

When I request e-signatures the form fields default to allow anyone to fill. I do not want clients to be able to fill or change this information. Because I have a lot of fields, it is very annoying having to individually change the cells to "prefill." I only need the client to fill their name and sign. Using ctrl and clicking the other cells does not allow me to change multiple fields at once.

Is there a way to allow the default setting on a form to pre-fill before requesting e-singatures, I cant stand how tedious it is to change each field everytime.

Had I known this would be an issue, I would have just used excel and then converted it to pdf when signatures were required. But I spent so much time formatting this form in acrobat that there must be an easy solution to this problem, any help is appreciated.