Getting to Rob Lucci is simple.
[taken from GameFAQ's One Piece guide]
Magnetic Stone x 1
Glue x 2
Mysterious Plant Fruit x 5
Magnetic Stone - Found near the wrecked ship in Jungle Zone. It is in a
Treasure Chest on a cliff to the left of the wrecked
ship. You need to use a mushroom below the cliff to
reach this Treasure Chest.
In case you don?t have any Magnetic Stones with you, you
can kill those Giant Purple Robot and hope for Magnetic
Stone to drop. (Chances of Magnetic Stone dropping is
low though)
Glue ? To make Glue, you need Sticky Sap x 1 + Spider Web x 1
Spider Web - You can get Spider Web in Jungle Zone or Ruins Zone
Sticky Sap - The first thing you need to do is to catch a Hercules
Beetle. Hercules Beetle can be found on one of the
trees outside the Cave. Sticky Sap is dropped after you
catch a Hercules Beetle
Mysterious Plant Fruit ? Destroy the electric trees in Dimension Zone to get
Mysterious Plant Fruit
thats how you get to Boss 1 in the Land to Heaven
Yo.