this is what i currently have for my last name search

Private Sub SearchByLastNameBtn_Click()

    Dim S As String, LN As String
        
        S = InputBox("Please enter Customers Last Name", "LastName")
        If S = "" Then Exit Sub
        
        LN = Nz(DLookup("LastName", "CustomerT", "LastName LIKE ""*" & S & "*"""), "")
        If LN = "" Then
            
            DoCmd.GoToRecord acDataForm, "OrderEntryF", acNewRec
            DoCmd.GoToControl "FirstName"
            
            Exit Sub
        End If
        
        Me.Filter = "LastName LIKE ""*" & S & "*"""
        Me.FilterOn = True
        
End Sub

Do you want it to always search firstname or lastname? Or only sometimes? There's a lot of ways to do it, you could do a combo box to select if you want to search by first or last if you want, or checkboxes, or there are other options.

But, if you just want to search by first or last name, either at the same time, always, the simplest way is just to add an OR statement in there.

LN = Nz(DLookup("LastName", "CustomerT", "LastName LIKE ""*" & S & "*"" or FirstName Like ""*" & S & "*"""), "")

Use Concatenation to build the string.

    Dim S As String, LN As String, FN As String
        
    LN = InputBox("Please enter customer's last name", "Last Name")
    If LN = "" Then Exit Sub
    
    FN = InputBox("Please enter customer's first name", "First Name")
    If FN = "" Then Exit Sub

    S = "LastName LIKE ""*" & LN & "*"" AND "
    S = S & "FirstName Like ""*" & FN & "*"""
    
    Me.Filter = S
    Me.FilterOn = True

If you are searching on more than just a couple of fields I would recommend using Form fields instead of Input Boxes.

ok, thank you for the support, i will try both ways to see what happens, thanks again