The "factory default" number of worksheets created in a new Excel workbook is generally set to three. Your VBA code can explicitly set the number of worksheets in a new workbook.
'--- save the current Excel global setting
With Application
Dim oldSheetsCount As Integer
oldSheetsCount = .SheetsInNewWorkbook
Dim myNewWB As Workbook
.SheetsInNewWorkbook = 1
Set myNewWB = .Workbooks.Add
'--- restore the previous setting
.SheetsInNewWorkbook = oldsheetcount
End With