Here's a sample paragraph using both simple past and past continuous tenses with time expressions:
Last week, I attended a workshop on digital storytelling. It started on Monday morning and lasted for three days. On the first day, we learned about narrative techniques and video editing. While the instructor was explaining the software, some students were still installing it. In the afternoon, we created short scripts in groups. On Tuesday, I was working on my storyboard when the lights suddenly went out. We had to wait for an hour before the power came back. On the final day, we presented our stories. I felt a little nervous, but everything went smoothly. After the event, I went out for dinner with some new friends I made there. It was a fun and productive week!