Two nights with a late arrival on day one is a pretty short trip, but fine given OP says they're not interested in gambling.

Dayclub/nightclub choice should depend on music preference and specific DJ who will be performing. Obviously it's always easier to go to a place on-property (esp. pool parties), but it's not like you're not going to just take an uber/lyft to whatever club you are going to. I can't stress enough that you need to make arrangements prior to arriving at the club; either buy presale tickets or contact a reliable host to make sure you will get quick entry. I think that checking out the big busy nightclubs is a reasonable part of a first Vegas experience, but if you're not into the big crowds, there are also a number of good lounge options.