You really haven't given enough information to go on, as to either the path or what these 'forms' are.
Here's some code to get you started. It assumes the desired filename is in the first content control in the document and that you want to save the file to the user's 'Documents' folder. The first sub pops up a populated SaveAs dialogue; the second simply saves the file without prompting.
Code:
Sub SaveDocAsPDF1()
Application.ScreenUpdating = False
Dim StrFlNm As String
With ActiveDocument
StrFlNm = .ContentControls(1).Range.Text
With Application.Dialogs(wdDialogFileSaveAs)
.Name = "C:\" & Environ("UserName") & "\Documents\" & StrFlNm
.Format = wdFormatPDF
.Show
End With
End With
Application.ScreenUpdating = True
End Sub
Sub SaveDocAsPDF2()
Application.ScreenUpdating = False
Dim StrFlNm As String
With ActiveDocument
StrFlNm = .ContentControls(1).Range.Text
.SaveAs2 FileName = "C:\" & Environ("UserName") & "\Documents\" & StrFlNm & ".pdf", FileFormat:=wdFormatPDF
End With
Application.ScreenUpdating = True
End Sub