Law enforcement is an interesting field, because, while all officers need to possess the same set of basic skills, which, they will learn in the academy, it is our unique differences that make us a team.
So, starting out, you want to keep a good reputation. Be honest and dependable. Stay away from people who don't believe in obeying the law. Pay your bills. Avoid drugs. Finish school. Learn to stay calm under pressure. You don't want to be known as someone with a temper. Work on developing good writing skills in school. So much of what we do is report-writing. Also develop and maintain your physical conditioning. This includes strength, flexibility, and cardio. All 3 are important. Be nice and polite to everyone. A background check will usually include interviews with your school, neighbors, employers, and maybe ex-girlfriends!
The hiring process is intense, and, barring any major disqualifiers, even if you get turned down at your department of choice, you should eventually find a department to hire you.
Getting past all that. . . when I say we all have differences and that is what makes the team: We had a guy who had been a tractor-trailer driver, and another who had been an electrician. There were times I needed to call on them for help. It's good to know the skills of your fellow-officers! I actually had an 18-wheeler blocking traffic because it was a new driver and he took the turn wrong. Quickest solution? Get the officer with the truck driving experience to get it un-stuck!
Is there anything in particular you are concerned about as far as your qualifications are concerned?