That depends on where you are in the world. In the UK, there is no aerobatic 'rating'; however, individual hirers are at liberty to impose whatever conditions they please in order to allow you to borrow their A/c.
Frankly, you are well advised to take some instruction - if you're good, you'll learn more, if there are basics that need building, you'll find out. Aerobatics aren't intrinsically difficult; IMHO it is when things diverge from plan that you need to be on the ball.
You don't mention how your experience is gained - it is likely to be helpful, but not necessarily directly relevant to what you might be flying next.