I have several boards for different projects that I'm working on. Is there any way to have a board where I can see all my tasks/cards from these “child” boards? It is a mission to open every single board to see where I need to focus on.
Yes, you can click on your avatar icon (top right) and choose Cards (2nd item).
This opens the "Card View", which shows all cards across all boards and organizations that you are assigned to.