What goes into a sprint, and from where
The backlog is not a separate list but the "no sprint" view over the project's tasks: you sort it by column — on story points, say, to see what is estimated and what is not — set priority and issue type, then move the cards into the sprint by changing which sprint they belong to. A sprint is created with a name, a goal and a date range, started explicitly, and while active it blocks another one from starting on the same project. What the platform does not do, and it is worth knowing before planning: it does not compute team capacity for you — it does not subtract leave, does not reserve a share for maintenance and does not warn you when you pull in too much. The quantitative reference you have is measured velocity, compared against the story-point total you have just gathered in the sprint.
Burndown: what the ideal line shows
The burndown is computed over the sprint range, day by day. For each day the platform counts the points and tasks that were not yet finished at the end of that day and draws them next to the ideal line — the straight descent from the point total to zero over the sprint duration. Completion comes from a marker set automatically when a task enters a "done" status and cleared if it leaves one, so the curve does not depend on a manually declared percentage. A task never counts partially: a 5-point task that is half done stays 5 points remaining until it actually reaches "done".
Velocity, and what you can do with it
Velocity is computed only over the project's closed sprints: for each one, how many story points ended up finished, plus the average across them all. That is the figure you plan with — not the average of what you intended, but the average of what came out. Two things matter when reading it: velocity is not normalised to sprint length automatically, so compare sprints of similar duration or account for the difference; and tasks without story points count as zero, so a sprint full of unestimated tasks will look artificially weak. Both are solved by estimation discipline, not by a setting.
What 4myprojects does not do at planning
Planning here is deliberately plain: backlog, story points, a sprint with a goal, burndown, velocity. There is no RICE or WSJF score and no automatic backlog ordering — the order is yours, through priority and through what you choose to pull into the sprint. There is no planning poker, estimate voting or asynchronous estimation session. There is no scope-creep detection: a task added after the sprint starts enters the burndown like any other and shows in the activity log, but is not flagged separately in a report. And there is no assistant of any kind that prioritises or predicts — the project indicators are fixed formulas over your own tasks.