Hi there, (just to help you with terminology: Actors are within the Level, Components are within the Actor)
If you have lost your component out of sight in the viewport, you can focus it (centered and zoomed in) with the shortcut F. Just select the component in the Components Tab, make sure to click into the Viewport and hit F.
You can also hide Components as well:
Select your Component and check the “Visible” Property if it is set to true (for visibility in editor viewport), and if “Hidden in Game” is set to false (for visibility in game).
Level Viewport supports focusing and visiblity as well. Just select the Actor in the World Outliner and hit F or check the properties for visibility in editor / game.
Since you say you are new to UE, you are probably flooded by tutorials already. If you are looking for short and compact tutorials without exhausting overhead, I would recommend you these tutorials from the UE channel:
hth 