Telerob.. As is often the case, your profile reveals nothing about you so it is difficult to offer much advice. An aviation background of some sort would almost certainly help.
ATC is a highly skilled job and not everyone can do it. You don't have to be particularly clever or incredibly young but, as already suggested, age is not on your side. Those who become controllers in their 20s can often still do an excellent job in their 40s, 50s and later because they have "grown up" with the job. However, to start from scratch later in life can present problems and you may find that you get through the initial training but experience problems when you start live work. Unfortunately, no clever tests have yet been devised which will prove one way or another if a person will eventually validate.
Good luck, work hard and I hope you make it.