Set about
Definition 1 of 2
Pro Tip 1/3Energy and Desire
Expresses enthusiasm or strong willingness to do something. 
She set about learning Spanish with unabated zeal.
Pro Tip 2/3Initiating Action
Implies the beginning of an action or process. 
Right after the meeting, we set about implementing the plan.
Pro Tip 3/3Purposeful Activity
Suggests a deliberate and focused approach to an activity. 
The community set about organizing a fundraiser.