Well, the starter islands aren't specifically about learning crafting, but they are where you should go first after the intro/tutorial in order to learn the game as a whole (as well as leveling up, gaining skill points, and getting the beginning of your alliance's storyline).

The exact quest and location of the quest giver to send you there depends on what alliance you are, but for all three alliances there should be a quest giver just a little outside where you first woke up after Coldharbour. This quest giver will tell you to go to a boat or ship at the docks of the city where you are, and take passage to the (first) starter island.

For Daggerfall Covenant this will send you to Stros M'kai and start off the main questline for that zone. Finishing the main questline for that zone will send you to the second starter island (Betnikh), and finishing the main questline for Betnikh will send you back to Daggerfall in Glenumbra.

For Ebonheart Pact this will send you to Bleakrock Isle and start off the main questline for that zone. Finishing the main questline for that zone will send you to the second starter zone (Bal Foyen), and finishing the main questline for Bal Foyen will send you back to Davon's Watch in Stonefalls.

For Aldmeri Dominion this will send you to Khenarthii's Roost and start off the main questline for that zone. There's only one starter island for Aldmeri Dominion (but it's bigger so it has about the same content as the other alliances get), so finishing the main questline for that zone will send you back to Vulkhel Guard in Auridon.

In all cases, I strongly suggest you fully explore the islands before completing the main questlines there and moving on. You'll discover multiple side-quests this way, as well as areas of interest and sky shards.