There are two ways to create the effort task - TEC1053847 describes one way, for when one has accidentally removed the 'effort' task, re-ID'd it, etc.
The other way is to start allocating staff to your project before creating tasks on the WBS. If you allocate resources first, CA PPM will assume a task must exist and create the effort task for you, giving it the ID "~rmw" - this, years ago, was known as a 'fast plan' and CA PPM will take care of assigning your staff to this ~rwm task for you. As long as you avoid creating other tasks, you are effectively booking actuals to the project since the one task is basically equivalent to the project.
You can create additional tasks, and book to these - however, the forecasted work is still coming off the ~rmw task - its just the way it works. Remove the tilde or the entire ID and you're back to a 'power plan,' using the full WBS for planning and actuals.
Otherwise, as others have mentioned - don't use projects, use something else - use a Product, Asset, Other Work to book time to - no tasks, no milestones, just one line entry ever possible on one's timesheet - easy, peasy.
When CA PPM creates the ~rmw task for you, depending on the vintage of CA PPM, you may see different results - older versions just create an "Effort" task, while newer versions create a task using the name of the project as the task name. So, maybe, seeing a task name that is equal to the project name is what you remember seeing - thinking that one was then booking to the project?