Hi Alexia Prat,
Thank you for your purchase.

 In Optional column settings select ascending/descending option for column that you want your table to be sorted on page load.

Hi Alexia Prat,

You can add this code on page where your table is located:

<script>
jQuery(function(){
    jQuery(document).ready(function(){
        wpDataTables.table_1.fnSettings().aoColumns[0].bSortable = false;
        wpDataTables.table_1.fnSettings().aoColumns[2].bSortable = false;
    });
});
</script>

Just change the numbers in aoColumns[0] by your needs. Number 0 is first column, 1 is second and so on...
Let me know if you manage to achieve what you wanted.

Hi Alexia Prat,

Sorry for misunderstanding.
If you are talking about this table -Link my suggestion is that in CSV file you make another column ( for example ID) and type the numbers in it. 
Next step is that in Optional column setup for that new column select ascending/descending and uncheck the visible option for that column. In that case the table on page load, sort order will be for that new column ID which will be hidden. But you will need to type ID's for your current table.

If you have some issues please send me that file so I can help you out.