VBA Macro To Name Sheets Based On Lookup Results

I want to name three sheets (sheets will have a different name every month so I refer to them below as Sheet(1), Sheet(2), and Sheet(3) (Their sheet index)) using a vlookup in VBA. I want the code to promt the user for input and based on the entry, I want to use a vlookup to name the sheets. There are three "lookup tables" on a sheet named "Ref" that I have defined as Table1 (used for naming Sheet(1)), Table2 (used for naming Sheet(2)), and Table3 (used for naming Sheet(3)) that I want to reference in the code. I also want a code to check the first MyLookUp1 which I have attemped below, but I do not know if I am doing this correctly. Below is my bad VBA attempt so you get an idea of what I am trying to do. Also, attached is an exaple file.

Sub namesheets()
Dim MyEntry As Variant
Dim MyLookUp1 As Variant
Dim MyLookup2 As Variant
Dim MyLookup3 As Variant
Dim MySTRING As String
MyEntry = Application.InputBox( _
Prompt:="Please enter an Item:", _
Title:="Lookup sheet name", _
Type:=2)
MySTRING = MyEntry
MyLookUp1 = Application.VLookup(MySTRING, Table1, 2, False)
If IsError(MyLookUp1) Then Exit Sub
Sheets(1).Select
ActiveSheet.Name = MyLookUp1....................