due to the several methods to create a form in MS Word, we need an example document to help you efficiently.
If the form is like a table, where the Text (first name) is in the first column and the form field itself in the second column, then you can just select the formfield in the second column and delete it or just replace it with your first name.
If the edit field cannot be deleted, then put the cursor on it and press the context menu key. Then press downarrow until you hear something about “edit control” or something like that. Open that dialog and Edit there your text.
Von: email@example.com <firstname.lastname@example.org> Im Auftrag von prem.translator@...
I recieved a form which is the templet for my Thesis. However, when I open the document I pressed enter and type down some information, it seems that the information didn't appear in the edit box, but before it. Moreover, it appeared one line for each information instead of in the same line like in the form.