The first thing we should do is to create the “Product Backlog”. It’s the list of features we have thought about for the project. It’s the definition of the scope.
However, Scrum is not predictive, so we do not plan upfront. Instead of creating a complete Product Backlog, we just add enough items for the next few cycles (aka iterations or Sprints). Then we will start the first cycle and keep updating the Product Backlog “adaptively”.
One of the Agile principles is simplicity. We prefer to create the Product Backlog on a physical board, rather than using software. Index cards or sticky notes are used to capture the Product Backlog items. We use sticky notes so much, that once someone asked me, quite seriously, if 3M had been the inventor of Scrum!
So, what should be the items in the Product Backlog? Is it OK, for example, to have something like “create the solution architecture”?