Can i start a sentence with so ? or will that be consider a error

if you are just jumping into a thought then it isn't wrong.

example:

So today Dustin and I

if you are doing a proper sentence then yes it is considered and error

well,

i dont learn that but this link might you out !

link -->

hope this : )

i have heard the mermaids singing, each to each.

i do not think they will sing to me