Imagine a man is going to get married and his close friend sees that the girl his friend has chosen is not a good one [By accident, he (the friend) knows the girl's background in detail] and wants to warn his friend about that girl (but very openly and in a debate). Please have a look at my self-made sentence and let me know if the bold preposition is a correct one or I have to modify it:
One hundred people have had their go at her before you.
Note: the number "100" here is a type of exaggeration to show an emphasis of the severity in my language and have no idea if it works in AmE.
The only source I found which actually provides an example of usage comes from Urban Dictionary under the entry of "go". leverichm suggests that with or at are the most appropriate prepositions to use.
If the OP wants to this expression, then I suggest that he rephrase it as:
A hundred guys have had a go at/with her before you.
Is BrE and has many different meanings all relating to "trying to do something"
We are placing bets on the Liverpool game. You want to have a go mate?
If you were to say
A hundred guys have had a go at her before you. she has slept with a hundred guys
You could be saying that a hundred guys tried to marry her before your friend did, but it would probably be understood that you are basically calling her a slut since "having a go at someone" means you are trying to bed them.
and your friend might say back to you
Are you having a go (at me)?! are you trying to upset me/rile me up?
Both have the sexual meaning as well as preserving the original concept of "trying out" while still being euphemism rather than an explicit statement.
I agree with Mari-lou A that "go at someone" usually means to attack, but it also has a meaning of intense sex (eg. the two were going at it hot and heavy) in a different sense than in the original post.