Short answer: Click the event in the timeline. The playhead parks exactly on that step and the stage renders exactly that moment - the right backdrop, sprites, and text, with no replaying from the start. This works for every kind of event, including silent ones with no visuals of their own, and the playhead never refuses a click.
Click any event in the timeline
Every event in the current scene is a card in the timeline on the left. Click one and the stage shows the game precisely as it stands at that step. Clicking around like this never resets your story variables - they carry along as you move, so the frame you see reflects the path you've been taking. (The one action that does reset them is Start over - see How do I restart playback from the beginning?.)
Auto-advancing events wait for you
Some events normally advance on their own - a timed pause, an effect. Clicking onto one of those holds the playhead there until you advance manually, so the moment doesn't slip away while you look at it. When the same event is reached by normal playback instead, it advances by itself as usual.
Jumping to another scene
Click a scene in the strip along the bottom, or use the scene pills, and the playhead parks on that scene's first event. From there you can click any event inside it.
Clicking a jump event
A jump event sends the story to another scene. Click one while Live and Forge follows it, landing you at its target. While Paused, the playhead stays on the jump itself and shows the frame going into it, so you can edit where it points without being carried away.
Conditions never lock you out
If the event you click sits behind a condition, Forge shows it to you anyway - the condition on the clicked event is bypassed so you can always inspect and edit it. Conditions still work normally during regular playback; this is purely so no event in your timeline is ever unreachable to you as the author.