Use 'embark upon' when starting something new and challenging with a sense of adventure. After years in research, he decided to embark upon a teaching career.
Pro Tip 2/3
Serious Undertaking
It implies a serious commitment to a new task, often with a considerable investment of time or effort. The team decided to embark upon a thorough analysis of the data.
Pro Tip 3/3
Metaphorical Journey
'Embark upon' is often used metaphorically to suggest the beginning of a journey or quest. She embarked upon a quest for knowledge and truth.