Formal:
* Faire le premier pas: This is the most literal translation and is suitable for formal situations.
* S'engager: This means "to commit" and implies taking a concrete action towards a goal.
Informal:
* Se lancer: This means "to launch oneself" and suggests taking the initiative.
* Passer à l'action: This means "to take action" and emphasizes the need to act.
Here are some examples:
* "Faire le premier pas vers une solution." (Take the first step towards a solution.)
* "S'engager dans un nouveau projet." (Commit to a new project.)
* "Se lancer dans une nouvelle aventure." (Launch oneself into a new adventure.)
* "Passer à l'action et faire quelque chose de positif." (Take action and do something positive.)
The best way to choose the right phrase depends on the situation and your desired level of formality.