Sidebar Questions

Hello, I posted recently with questions about my sidebar but was able to fix most of them. I now have a few questions: 1. How can I get the image in my sidebar centered? Please view this link to understand what I mean: https://otinsight.org/2018/11/14/5-jobs-for-relevant-experience-before-ot-school/ 2. Can I add arbitrary text to the sidebar using the playfair display font? 3. Can I get rid of some of the space between the image, text, and social media icons as seen in the link I provided? 4. How can I add a sidebar to the posts index page? When I try to add one in now, the sidebar appears at the bottom of the page rather than as an actual sidebar. My website is www.otinsight.org. Please advise