set out to (do something)
To begin to undertake a task; to attempt or intend to do something. Framed for murder and wanted by police, the lone detective set out to clear her name. We set out to create the most elegant and user-friendly smartphone ever made, and I think we did it.
set out to do something
to begin to do something; to intend to do something. Jill set out to weed the garden, but pulled up a few valuable plants in the process. I set out to repair the door, not rebuild the whole porch.