To add activity, tap on "+ Capture" in the bottom Navigation bar and then tap on Movement. Here you can select movement type, start time, duration, and add a note.
Tip: Once you have added a specific movement, it will shop up in the Quick add list on the bottom of the page. You can quickly re-add movement and duration using this.
You can also add movements by enabling Sync with Apple Health on Apple devices.
To edit the date, duration, or activity, this can be changed by tapping on the movement icon on your path.
To delete, tap on the activity icon to enlarge it, and in the upper right corner, the three dots will allow you to delete the activity.