I don't see why your first fish couldn't be a pair. Just don't add a bunch of fish at once.
My first fish (33 - gallon) were two yellow-tail damsels. I still have them a year later and they're model citizens in my tank, even after being moved twice, from a 33 to a 55 and then from the 55 to a 90, but others have had experience with them turning mean.
I would think a pair of clowns (small) or a pair of firefish (small) would be fine.
Fish to avoid until tank is more established would be:
filter feaders (sand-sifting gobies/mandarins/etc)
six line wrasse (they like to eat pests of which you probably don't have any yet)
pygmy/dwarf angels (they like to graze on LR and you probably don't have much algae growth yet)