I guess you refer to the mushrooms confiscated by Storm. You have to train with her (afternoons), and eventually you will infiltrate at her house at night.
You need the bubble-gun (the bagpipe in the Stinky Bog). To use it, you have to do the Meteorite side-quest, which is unlocked once you break her drum (as a part of Vexy side-quest).
Regarding the spears and the axe, you can have multiple spears because they are spent as you use them, while you can use the axe as many times as you want.
An for the handiness essence, you can get it from Lily and Meteorite.
To increase any skill, you just have to get essence from the Smurfettes (that is, you have to engage in frisky situations with them). In the particular case of strength, you can get it from Sassette and Storm; at the beginning of the game, the easiest way is by playing with Sassette in the slider, once you have some heart points with her there's an option that will give you strength essence. In addition, when you visit Blossom in the afternoon, you will gain points in a random skill.
Thank you very much for your interest in the game! I hope you enjoy it!
Regarding the presence of several Smurfettes (based on the recent movie "Smurfs: The Lost Village", and some comics), you can consider that a poetic license...
