Both of those phrases are wrong. You cannot use 'Here goes' or 'Here it goes' when you are giving something to someone. You seem to be confusing 'Here is.....' with the more colloquial 'Here you go'. In informal spoken English, you can say 'Here you go' or 'There you go' when you hand something over. In an informal message to a friend, you could also use one of these. For example, if a friend asks you for a photo, you could send the photo along with the message 'Here you go'. I don't think that 'Here/There you go' would be appropriate for business correspondence, unless the business culture where you work is very informal. A simple, neutral message would be 'This is ...' or 'Here is...'. followed by an explanation about what you are attaching. A more businessy message would be 'Please find attached ...'

i think here it goes is slightly more formal, i think your should use that one if you are writing a formal text

i think here it goes is slightly more formal, i think your should use that one if you are writing a formal text