Enlisted nuke aiming for officer

[Someguy1999]

I have recently started A school as an EM and I am highly considering applying for sta-21. I wish I would have gone officer right from the start, but having just finished highschool I didn't know what I wanted to do with my life yet. I walked into the nearest recruiters office and three weeks later departed for bootcamp. I want to maximize my time in the Navy, twenty plus years, and am realizing that it would be a great step in my career to go the officer route. What are my chances for getting in with an average GPA in highschool as well as ACT. If I fail to get accepted the first time, am I allowed to keep applying? If I finish top or near too of my class in A school/Power school will that affect my chances of getting accepted? I greatly appreciate this forum and the answers I have found while lurking. All answers, even those I wouldn't want to hear, are greatly acccepted.