SF_10.1, SF_10.2, SF_11.0, SF_11.1, SF_11.2, SF_12.0, SF_12.1, SF_12.2, SF_13.0, SF_13.1, SF_13.2, SF_13.3 - https://docs.sitefinity.com/tutorial-create-a-content-block-widget-that-displays-shared-content

CreatePageWithSharedContentItemSnippet.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Telerik.Sitefinity.Abstractions;
using Telerik.Sitefinity.GenericContent.Model;
using Telerik.Sitefinity.Modules.GenericContent;
using Telerik.Sitefinity.Modules.Pages;
using Telerik.Sitefinity.Pages.Model;

namespace Telerik.Sitefinity.Documentation.CodeSnippets.DevGuide.SitefinityEssentials.Modules.ContentBlocks
{
    public partial class ContentBlocksSnippets
    {
        public static void CreatePageWithSharedContentItemSnippet()
        {
            //gets an instance of the contentManager
            var contentManager = ContentManager.GetManager();

            //creates new content block
            var contentItem = CreateContentItem(contentManager);

            //gets a PageManager object
            PageManager manager = PageManager.GetManager();

            //creates new page
            var pageData = CreatePageData(manager, Guid.NewGuid());

            //edit the page to add content block
            var draftPage = manager.EditPage(pageData.Id);

            var contentBlock = new Telerik.Sitefinity.Modules.GenericContent.Web.UI.ContentBlock();
            contentBlock.Html = contentItem.Content.Value;
            contentBlock.SharedContentID = contentItem.Id;
            var draftControl = manager.CreateControl<PageDraftControl>(contentBlock, "Body");
            draftPage.Controls.Add(draftControl);

            //Create a node in the SiteMap for that page. 
            PageNode node = manager.CreatePageNode();
            var parent = manager.GetPageNode(SiteInitializer.CurrentFrontendRootNodeId);
            manager.ChangeParent(node, parent);
            //set the node properties
            node.Title = "page title";
            node.ShowInNavigation = true;
            node.UrlName = "url";

            //associate the node with the PageData object

            //valid before 7.0
            //node.Page = pageData;

            //Save the changes
            manager.PublishPageDraft(draftPage);
            manager.SaveChanges();
        }

        private static ContentItem CreateContentItem(ContentManager contentManager)
        {
            var contentItem = contentManager.CreateContent(Guid.NewGuid());
            contentItem.Title = "content item title";
            contentItem.UrlName = "content-item-url-name";
            contentManager.SaveChanges();

            //valid before 7.0
            //contentItem = contentManager.Publish(contentItem);

            //since version 7.0 you must use the Lifecycle property
            contentManager.Lifecycle.Publish(contentItem);

            contentManager.SaveChanges();
            return contentItem;
        }

        private static PageData CreatePageData(PageManager pageManager, Guid id)
        {
            //It holds the actual page contents
            PageData pageData = pageManager.CreatePageData(id);
            pageData.Template = pageManager.GetTemplates().First();
            pageData.HtmlTitle = "page title";

            //valid before 7.0
            //pageData.Title = "page title";

            //since 7.0 some of the PageData properties are moved to the PageNode
            //check API Changes in Sitefinity 7.0
            pageData.NavigationNode.Title = "page title";

            //Set the page status as published. The default status is draft
            pageData.Status = ContentLifecycleStatus.Live;
            return pageData;
        }
    }
}