How to list answer preview in fillable form

I'm working on building a basic fillable form for a wellness pledge, but would like the fillable portion to preview the answer before someone clicks into the box, and then have the preview disappear so the person filling out the box can write in his/her own response.

For instance, if the pledge were to begin,

" I, [Insert name here], pledge to... from [insert start date here] to [insert end date here]... "

When a new person is viewing the form, I would like for the "[insert name here]" text to be showing in the fillable portion of the document until the person clicks in that text box, and then the preview would go away and he/she could actually type out their name. Is there a way to do this? Attaching an example pic so you can see what I'm talking about.

Any help would be appreciated, thanks!