There's only one Open this coming year, six months on the heels of the last one meaning the rules have changed and you need to strategize in a totally new way.
If this is it for your functional fitness competitive output this year then give it all you've got. Use pacing and singles to finish the Open like a boss.
It takes adult levels of dedication and time to become a teen athlete at the highest level but, you're still a kid. Your training is going to have to be well thought out.