wow, I am really surprised the balancer didn't give you sea luxuries. I've never seen a single-lux start like that. This looks really fun, can you please post save?
but I'd probably settle on the plains between the hills.
Me too. Your main pain here will be crappy production. As tempting as it is to settle on the hill I wouldn't. If you leave all the hills you can mine them later for a better production and have forests to chop for production boost. If you settle on one of them you have neither. Settling on plains makes the yield the same as a farmed plain, which is all that will yield until fertilizer.
The start will be difficult due to growth and isolation so you need lighthouse and disembarkment ASAP. I'd beeline optics. Don't even open the library tech, you'll be growing too slowly for a library to do you much good until a lighthouse. then it will be great. Looking at the terrain a +2 food from fish is a crappy start for hammers. I might do this until I grow to pop 2 then take the forested hill of silver next. It will yield some nice gold +1 food and +1 hammer. Sheep next. production will be too terrible if you work more than 1 unimproved fish.
Tech Order: Pottery-->Sailing-->Optics-->mining/writing-->calender-->philosophy-->animal husbandry (you don't need ANY military until you get off-island and start exploring)
With a start like that, you NEED God of the Sea. Obviously tradition for tenets.
build order: monument, start work on scout if you finish, switch to shrine as soon as pottery is completed and cross fingers for pantheon, build granary, finish scout and keep building them until sailing is finished, then: 4 work boats in a row (gotta grow as quick as possible) route them in a way that explores a bit farther as you move them into position on the fish. worker isn't even worth it as you can't chop forests and there is only 1 tile to farm possible, trireme to explore, then, when optics finishes, embark warrior and your waiting scouts and find CS as quick as possible. Maybe another trireme, library and worker after mining. AS SOON as you find a nice nearby spot settlers, settlers. If there is anything in range, build trade ships immediately as you'll be suffering badly on gold.