Once your plan is up and running, you're just about ready to plan more work for your teams. Most likely, your plan will already have issues in it, based on the issue sources you've previously selected.
You may also need to create more issues, to accommodate high-level work as they come. In the new experience, we're making it more straightforward and intuitive for you to create issues directly in your plan.
Note that at any point in time during planning, you may just be planning high-level work — and that's fine. This essentially means that during high-level planning, it's typical to have placeholder estimates, and even skip specifying issue details, like assignees and target dates. Your teams can define more accurate values for these details later on.
Also, note that it's easy to lose focus when you're planning work across multiple projects, releases, teams, and other factors. We recommend you filter the work in your plans, so you can focus on a specific part of your work, as needed. See Viewing work for more details.