Option Explicit

Sub test()
    Dim x, i As Long, fName As String, newfName As String, Path As String
    x = Application.GetOpenFilename(, , "Select files to rename", , True)
    If IsArray(x) Then
        Path = Left(x( 1 ), InStrRev(x( 1 ), "\")) & "New\"
        If Dir(Path) = "" Then MkDir Path
        For i =  1  To UBound(x)
            fName = Dir(x(i))
            newfName = UCase(Left(fName,  1 )) & Mid(fName,  2 ,  255 )
            FileCopy x(i), Path & newfName
            Kill x(i)
        Next i
    End If
End Sub

Sub test2()
    Dim x As String, fName As String, oldPath As String, newPath As String, newfName As String
    
    oldPath = "C:\New Folder\"
    newPath = oldPath & "New\"
    On Error Resume Next
    x = GetAttr(newPath) And  0 
    If Err.Number <>  0  Then MkDir newPath
    
    fName = Dir(oldPath & "*")
    Do While Len(fName) >  0 
        newfName = UCase(Left(fName,  1 )) & Mid(fName,  2 ,  255 )
        FileCopy oldPath & fName, newPath & newfName
        Kill oldPath & fName
        fName = Dir
    Loop
End Sub