The reason why you will hear different advice on Skimming Nano is because at this size tank it’s cheaper to just do water changes.
Skimming will remove organics and proteins before they start to break down. In return extending the water quality and times between water changes.
Also on tanks this small there’s not much room for a skimmer unless you use a sump.
You could do hang on back models, but like I said instead of spending a hundred bucks or more on a skimmer most people will just buy salt and do water changes.
On small tanks it’s easy to over skim as well, starving out some inverts and corals
Since this is your first saltwater setup I would recommend just start with fish and get the basics nailed down before you jump straight into reef.
This will give you time to learn and get the proper water quality established.
Salinity and temperatures are harder to maintain in small tanks without fluctuations and fish are more forgiving in that aspect compared to corals and inverts