I assume you want to have the homepage show only one item, from a specific category called "Home". You want the items on the homepage to be shown with a template named "homepage". The other index pages will show the respective categories using the default/index template.
You also have ordered the categories and what them displayed in that order in the category list in the sidebar.
First, go to the Ordered admin page in the nucleus admin area, select your blog, then choose the Manage Categories tab. Here you have assigned an order to each category already. Now find the row for the "Home" category. In the Index Template field, enter "homepage" without the quotes. Do the same for the Item Template field, then click the Set button on that row.
Now, in the Skins page of the nucleus admin area, find the row for the default skin, then click the Main Index link to edit the Main Index skin part. Here you want to replace <%blog(default/index,10)%> with
Code: Select all
Now you need to edit the skins/default/sidebar.inc file (using the SkinFiles plugin, or a File Manager from your host). Replace <%categorylist(default/index)%> with <%Ordered(categorylist,all,default/index)%>
That should get you close.