It is not easy in the least to become a film editor. This is mostly due to very steep competition. Because many people perceive being behind the scenes of TV shows and films as glamorous, there are many people who aspire to get a job in film production. All of these people make for a very busy competition.
It is fairly simple, however, to acquire most of the skills necessary before heading out and applying. The one with the best skills, undoubtedly, will be the one who becomes a film editor. Be warned, the job hours can be erratic and the job itself can be quite stressful.
The best start a person can have in achieving their goal is to go to film school or by studying television production. Classrooms are definitely one of the best places to learn the proper terminology for the various aspects of the industry, in addition to learning the fundamental skills in camera work, editing, lights and sound. It'll take awhile, but such is the way to become a film editor.
It can be very frustrating to get that first job as a film editor. A good idea to start with is by working for free for an independent company willing to take you on. This will help you get your foot in the door and build your resume when you go out and apply for bigger jobs later on. Should any offer come to you, whether they want you to become a receptionist or take on an entry level position for a production assistant job, do not turn it down. It never hurts to get to know people in the industry; in fact, it is key.
Tell everyone you meet that you aspire to become a film editor. You never know just which person you tell might be in need of post production assistance or knows someone who needs such. Turn that production assistant job into a post production assistant position. Take those skills and become an assistant editor. Take those skills and make yourself an editor. While it won't happen overnight, it is by no means impossible.
One helpful idea is to learn Avid. Nearly all Avids are run on Apple Macintosh computers, so save your money and buy yourself one. What is the purpose of learning Avid? Avid technology is what most TV shows and films are cut on. Once you've purchased a Mac, install FinalCut Pro. This is an industry standard. Learn and familiarize yourself with how the Macintosh operating system works. Online arts programs can help you master this software. You will notice an increasing number of employers seeking FinalCut Pro users. Once you've gotten to know the software at home, it'll be that much easier to use at the workplace.