You should cut the path off at the end of the first island and then start off by building a Steel Mini Roller Coaster because it is a cheap roller coaster, and it should roll in some money. Set the research priorities to Shops and Stalls until you get the Information Kiosk, as it will become necessary to prevent guests from getting lost later on.
Second, build all of the thrill rides you have, then build a small roller coaster - this will attract about 350 people. Now, if you want to, you can join back the path to the two other islands - and if you do, join a path up from the first island to the third, or build a Chairlift to make some extra money.
Once you have done this, you should hire two of all the staff, and you may have to hire a third Handyman. You will also have to build at least five Bathrooms in all, and build two groups of shops. Keep building new rides and the occasional roller coaster, and hire new staff periodically. By the end of Year 3, you should have completed your goal.
Tip: If things are getting cramped up on the islands, consider building beneath them, underground. This is tricky on the first one, but the other two have a decent amount of volume for construction. If you build low enough, you can even go beneath the water, essentially freeing you from a constraint to one island.