Here's some extra info on how to find the required ingredients in the tutorial level:
Glass bottle - In the chest next to the brewing stand
Water - Next to the chest mentioned above
Spider eye - Randomly collected when killing a spider at night
Sugar - Collect sugar canes which are tall green plants found near water usually. Next create sugar from the sugar canes on a crafting table.
Brown mushrooms - Found easily in grassy areas, the game specifies them as simply "mushrooms" not "brown mushrooms".
Redstone - Found in a chest just before the castle in an underground passage
Gunpowder - Kill a creeper at night, it must not explode otherwise it won't drop any gunpowder. Kill it with arrows ideally.
Apple - A random drop from trees, "mine" the leaves on green trees to find an apple. Alternatively go to X -176, Y 66, Z 121 to find some apples in a chest (credit to SilentlyForgot).
Gold - There are a few blocks of gold at X -281, Y 74, Z 243. You need some form of explosives to obtain these. Also near this temple in the desert is another temple where 4 chests are found by mining beneath it. The co-ords for this are -310, 66, 105 (credit to W1LLYMAN). You have to avoid the blue block in this area between the chests as it explodes.
Also, play on "normal" as zombie villagers are more likely to spawn (50% chance on normal and 100% on hard). Alternatively you can lure some zombies to villagers to "infect" them.
UPDATE: At the moment I have a game world with the 2 finished items (splash potion of weakness + golden apple) available along with some trapped zombie villagers. If you want to boost this please add & message me on Xbox One (not on the TA website).
I no longer have this world available. Thanks to everyone who joined and left feedback.
In total I helped 118 people in getting this achievement.