it's that simple. as long as the store stuff doesn't have preservatives such as potassium sorbate. juice from the juicer will ferment quite happily on its own, you might want to add a campden tablet / potasium metabisulfite, read up on basic cidermaking if you wonder why.
as for the apples, search around the forum, everyone has their preferred varieties. there is an awful lot of information in this thread:
i don't know what exactly you mean by "the Real Cider" so it's hard to say, but a standard strategy for a well rounded cider is to go for a majority of sweet apples (for fermentables), which usually don't bring that much flavor, your supermarket stuff will do for the sweet apples so maybe just concentrate on the other types: sharp apples for acidity, think of any tart apples like granny smith with their malic acid punch, and bitter or bittersweet for tannin and body, but tannin-rich cider apples are usually impossible to find unless you happen to have a tree that produces them, in which case they quite literally grow on trees. you can substitute a small amount of ripe crabapples for the bitters. so a starting guess would be 85% supermarket, 10% sour/tart/granny smith and ~5% (or less, depending on how bitter they are) grape-sized or prune-sized crabapples.