It may well be possible to become a mentalist and anyone with access to appropriate resources can indeed learn all possible mentalism tricks but it is surely not easy and therefore not for everyone. For the benefit of those who may not be too sure what mentaism entails, it is actually a mind game and mostly based on showmanship.
Just like magic tricks, mentalism requires invention of tricks and then regular practice so no one catches you in the audience when you try to technically fool them. There is nothing paranormal with mentalism as it is solely based on tricks which have been perfected and polished over the years in such a manner that anyone from the audience can not only be entertained but also, may go on wanting to become a mentalist.
If you are such a person then look online for resources on how to become a mentalist and you can learn how here. You will find plenty of material. If you are looking to take a professional route then you will want to pay more attention to how a trick is executed as opposed to fusing entirely upon tricks themselves.
On the other hand, if you merely want to know about the various tricks then there are several websites that can provide you with popular tricks used by mentalists. The two things that mentalists take seriously is guarding their secrets as well as taking the roughest trick execution procedures to avoid revealing their secrets.