Sidebar that works like a webpage page

Hi, how can I use the sidebar area to post text and media to things I’ve created? I am having great difficulty doing this with any of the available widgets and the text widget. I don’t need for others to be able to post or comment, I’m just using this site to create an online portfolio. Want 4 headings in a column and underneath stuff posted with thumbnails and explanation. I need just a page layout with a main area and a side area for putting content. Please help!