When you see the status bar says "Group of 2" then you can click Object menu > Ungroup. Next, deselect everything. And then you will be able to select it.
However, sometimes newbies will accidentally make a lot of groups. So after you click Ungroup, and you still can't select it, look again at the status bar. You might have to click Ungroup a few times.
If you have it fixed by ungrouping, then you don't need to worry about bitmap copy or clone (or a few other reasons). But there's still a chance (theoretically) that it was a bitmap copy which got grouped.
Edit menu > Make a Bitmap Copy can change a vector object to a raster object. If you did that, the status bar will say "Image....". If you did that, you can just delete it, and the vector object will still be hiding underneath, and you can select it.
If you made a clone by Edit menu > Clone (or clicked button on command bar or key shortcut) the status bar will say "Clone....". Then you can click Edit menu > Clone > Unlink Clone, and it will be a regular object as before.
(Sounds like I might need to make a little tutorial which lists all the different possibilities for not being able to select a single object. Seems like a common question lately
)