What is the destination of a Buddhist? Where should we go for the rest what is the rest ? In mundane life living is so tough , facing sorrow , troubles and need to struggle for achieve something physical things and we get hurt because craving. As I'm doing myself I'm feeling nothing and restless because craving and got nothing after craving and everything is over . So where to focus , what is aim of one Buddhist. I never practice and now I don't understand from where to start, not feeling to start.
What is the destination of a buddhist?


There is no particular destination a Buddhist aims for. The Buddhist goal is to be stress free eradicating the cause which is systematised as the 4 Noble Truths. Once you are stress free this is called Nirvana. The path to Nirvana is achived thought the 3 fold training.

Though the Abhidhamma classifieds Nirvana as a Lokuttara Bhumi, this is not a destination as such.


  Where should we go for the rest what is the rest ?


Rest is achived thought solitude. More on this see Viveka,nissita by Piya Tan.


  In mundane life living is so tough , facing sorrow , troubles and need to struggle for achieve something physical things and we get hurt because craving. 


Mundane life is tough because of the presence of unwholesome roots which drive us. Will (chanda) to achieve a goal in the absence of craving hence there is no unwholesome root associated with it. [(Kosambi) Unnābha Sutta, Sangarava Sutta] So you should have the will to discharge duties and attain worldly goals without craving.


  ... So where to focus ...


You should keep your focus on feelings or sensations.


  
    With contact as condition, there is feeling; with feeling as condition, there is craving.
    But with the remainderless fading away and ending of that same craving comes the ending of
    clinging;
  


Source: (Samuday’atthangama) Loka Sutta

Also from one of Goenka's research papers: Why Vedana and What is Vedana?


  
    Eradicate the latent tendency of craving using pleasant sensations (by equanimous observation of the pleasant sensations understanding their changing nature), eradicate latent tendency of aversion using unpleasant sensations and eradicate the latent tendency of ignorance using neutral sensations. 
  


Another passage from the same paper:


  
    Vedana is also a cetasikacetasika (mental concomitant). When the Buddha says, sabbe dhamma vedana samosaranasabbe dhamma vedana samosarana, it means that the experience of all mental concomitants includes and is inseparable from vedana. Hence according to my understanding of the teaching of the Buddha, not only do kayanupassanakayanupassana and vedananupassanavedananupassana involve the awareness of vedana but vedana also forms an integral part of dhammanupassanadhammanupassana and cittanupassanacittanupassana. A meditator whether practising kayanupassana or vedananupassana or cittanupassana or dhammanupassana, continues to be aware of vedana. He realizes the phenomenon of arising (samudayadhammanupassisamudayadhammanupassi) and the phenomenon of passing away (vayadhammanupassivayadhammanupassi) by maintaining awareness of vedana with the understanding of its impermanent nature. Thus he does not allow tanha to arise in response to vedana: He responds neither with tanha of craving towards a pleasant sensation nor with tanha of aversion towards an unpleasant sensation. A meditator maintains upekkha (equanimity) based on understanding of anicca (impermanence).
  


Ideally you should pratice the Vipassana to overcome craving and liberated your mind. You can try and take a course at http://www.dhamma.org/ or http://www.internationalmeditationcentre.org/. The level of support one can get in a forum or Q&amp;A site like this is limited. To get rid of your pain you will have to take a formal meditation course.