I'd say have a few days worth of sleepers to start (you'll be doing laundry every day anyway). Honestly, my son was in sleepers for the first several weeks. They go through so many clothes changes a day, that it wasn't worth putting my son in "outfits." And sleepers are comfy & cozy.
Just a word of caution: remember that you do not know how big your baby will be! I wouldn't get too many things in any one size at this point. My son NEVER fit in newborn clothes. He went right into 0-3 month sizes...and was in 3-6m at 7 weeks old, and 9-12m at 5 months. So, even if I had bought ahead of time, things wouldn't have fit, or would have been the wrong season (3-6m sizes should have been what he wore in spring/summer, but ended up winter clothes in that size, 9-12 should have been fall/winter, but were summer!!)
You could be the opposite, have a peanut, who will stay in premie and newborn sizes for a few months.
My 2 cousins clued me in on the above advice, though it was hard to NOT buy cute clothes, I am sooo glad I didn't. I would have just ended up wasting money on wrong sizes (my OB predicted him to 6#, but he was 8#12oz). My one cousin had a (full term) peanut at 6 pounds, and the baby was in premie for a bit, then newborn for a long while. The other had a larger baby like mine.
To be safe, have a few days worth of sleepers in newborn and 0-3, just to be safe, maybe a few premie, just in case it's a little baby! Keep those receipts!
Just my thoughts & experience!