Honestly I would just start with 7CS.
5CS is a dead game more or less. 7CS will have WAY more action and drawing to keep people interested.
In 5CS as soon as you take an unfavourable card you're basically obligated to fold. It rewards extremely patient, tight and disciplined play. A single pair will be the winning hand a majority of the time, straights and flushes won't realise their equity like they could being (rarely) dealt in 5 Card Draw because they'll fold on 2nd or 3rd Street before their hand takes shape.
It's not a ball of fun for a microstakes home game.
7CS on the other hand is a game where it's very easy to make a hail mary gin card on 7th street, or have players with 3 way (flush, straight, 2 pair or low if playing S8) draws on 6th Street. The additional ambiguity of 3 downcards also helps keep things interesting.
Another alternative that uses traditional hand rankings, can be played fixed limit, and is probably well understood by most players is 5 Card Draw. I have found recreational players love the lack of information and "gamble" that comes with playing "cowboy poker"