Criteria:
You are on a small island and around you are many other islands that you can quickly reach in a few seconds.
Nearby villages
large caves nearby
There are also some buildings underwater in some places.
First of all, you can easily influence the spawn point itself and thus also influence the biome near the spawn point.
Surface properties, such as an island and the like, can just as easily be influenced accordingly - even without a bed.
As far as villages and caves are concerned, all you really need to do is go to them, and if you have an island there, you set up your spawn point with a bed in which you let the character sleep once and you have it. The same can also be taken into account with regard to underwater buildings.
However, if you don't want to play in the creative mode, in which there would be no success, I would rather advise that you also attach importance to ore deposits, especially when it comes to rare ores such as emerald and diamond, but also iron, Gold, redstone and lapis lazuli.
Also nearby lava deposits can't do any harm to "pour" a nether portal and an explosion-proof house with it.
Take a look at YouTube e.g. Gaminguides often makes seeds
I actually always look up on Youtube: "Minecraft Insel See Top" and then there are videos with e.g. 50 islands and everywhere the corresponding seed. Maybe you like something there.
