Regarding speeed I’m not sure that groups vs components makes much difference, although the SketchUp online help suggests components are better in this respect: “Multiple instances of a component are lighter weight than multiple copies of an entity or group.” (Improving Performance | SketchUp Help). I tend to mainly use components and only use groups to temporarily isolate some geometry or groups of individual components.
Regarding the use of Tags, there is no rule that you have to use them. You can keep it simple (particularly when learning) by ignoring tags and control visibility via components (and/or groups) alone. As long as you have a well disciplined model with appropriately named components, then you can toggle them on and off in the Outliner. It’s one less issue to think about.
You can also control visibilty via scenes so you can combine various component visibilities depending on what you want to show for a particular aspect of your model. Whatever you make visible/invisible in a scene (e.g. front elevation, ground floor plan etc) will remain so unless you subsequently update the scene.