Likely neither will Ocean Ebcounters or GoWest as they have a no-solo policy. So that leaves about 2 dozen others to contact. Start with Relaxed Guided Dives as they're in a pretty convenient location on the main road just west of the airport. A partial list -
Curacao dive operators
The famous Tugboat is 17' deep. Snorkeled all the time. Entry is just off the beach. You'll need to bring tanks since the dive school only seems to be there occasionally. It's off one of the pilings and the other one is encrusted with orange cup corals. The pier on the other side is a good dive also - maybe a snorkel too, I didn't notice. Look at the area on Google Earth at the right zoom, you can see the tugboat location.
Varsenbaai is also good for both afaik. Trunk Divers on site, turtles in 6' of water just off the beach, seahorses near the mooring ball and we saw squid under the dive dock once, Also there's pontoon boat wreck around 80' to the south where most people turn.
Playa Jeremi is good for both, it's a good dive and the north side fo the protected cove is listed on Frommer's Best Caribbean Snorkels list - probably for the fire cup corals in about 12'. No facilities at that site.
Playa Kalki in Westpunt is a good snorkel north of the beach under the Lodge KH cliffs - there's flounder in the shallows and the coral is shallow.. GoWest is there though so they would see you trying to solo there - the shop is behind the dive dock.
I think, but do not know that it won't be an issue at Discover Diving in Lagun - I went there once by myself for tanks. They're at the entrance to Playa Lagun so they can't see the beach so ymmv.
That would be a decent snorkel under the cliffs on both sides of the protected cove and just outside turtles hang out waiting for scraps from the fishermen. Slightly deeper there.
Most of these are also snorkels - read the reviews.
Scuba Shore Diving Site Listing for: Curacao, ABC Islands
#'s 6 and 7 are no longer there and the Superior Producer is only dove at night escorted - it's in the cruise ship path.
Check with the Dive Bus also - they provide in-town pickup, a DM on the dive and snorkel options at all their dive sites.
I haven't been there for a few years but I doubt much has changed. I dove by myself at the old Habitat resort site - Habitat is not there any more - the resort is now a condo resort marketed to Euros and several dive operators have gone in/out. There's a swim platform there now.