what made us light candles outside our home during Nov. 1 and 2?  

Some people believe that lighting a candle will bring the souls back. I don't know if that might be the reason or not, but is the only tradition I have heard of that might apply.

We don't usually light candles outside the house just inside. But last year we put floating candles on a big basin and floated some flowers too to commemorate the deaths of our loved ones. The lighting of candles outside the house was just another way of lighting candles.
But I think most people light candles outside to ward off evil spirits or a symbol that the souls departed can see they were remembered. I really don't know.

I think some will light candles in remembering the celebrations of all souls and all saints day. They light candle in respect of the holiday celebrated.

Lighting a candles during that day is you are participating and celebrating the holiday season. You are also remembering the dead of someone from your past relatives who are dead already to pray for them.