See example here >>> http://webtricker.com/projects/e-Marefa-v3/

scroll to specific section on click in nav menu.js

(function($){
    $(function(){
        $('.main-nav ul li a').on('click', function(e) {
            
            $(".main-nav ul li").removeClass("current-menu-item");
            $(this).parent().addClass("current-menu-item");

            if($(window).width() <= 767 ){
                $(".navigation-wrapper").removeClass("navShown");
                $(".phone-nav").removeClass("change");
            }
            
            smooth_scroll_to(this.hash, e);
        });
    })
})(jQuery)


$(window).on('load',function() {
    scroll(0, 0);
    // takes care of some browsers issue
    setTimeout(function(){scroll(0, 0);},1);
    
    smooth_scroll_to(window.location.hash);        
    
});

    
function smooth_scroll_to(hash, e) {
if(hash === '') {
    return false;
    } else {
        if($(hash).length > 0) {
            
            if(typeof e !== 'undefined') {
                e.preventDefault();
                history.pushState(null, null, $(e.target).attr('href'));
            }
            
            $('html, body').animate({
                
                scrollTop: $(hash).offset().top - 83
            }, 2000 );
        }
    }
}