What height is that shelf? Generally you want your tweeters at seated ear height.
36 inches.
You could start with your all in one amp, and then some smaller inexpensive speakers intended for a second system later. ’Learn’ the room, mess with locations, heights, toe-ins. After gained knowledge (researching ’real’ speakers all the time), then more informed choices can be tried.
Good advice. Moving up gradually in speaker quality I'm sure would be an education in itself.
IF buying an amp first, consider ’extra’ power now IN CASE you might want to try some inefficient speakers (low sensitivity, below 90 db/1w/1m).
What would you consider to be 'extra' power? That's kind of what I thought I was doing by considering the Naim Nova (80 watts per channel) over the Naim Atom (40 watts per channel). Is that "enough?"