Insert string into empty list at a specific index

I realise that if my list is empty, I can't insert something at the 3rd index for example as it will return an out of bounds error.

So I tried to pad my list with null values. So if I wanted to insert something at the 3rd index, element 1 and 2 will be null to achieve this. But this seems so unnecessary... I was wondering if there were any alternatives or ways around this?