@Husseinisdoingfine I'm in no way an expert but this is how I would go about it.
First, the best tool to use is always the one you already have. (The one you are using right now to figure out what I meant by that) From the way you are asking, you are describing a vaporizer.
The instructions on how to use one are all over the internet. Be careful because vaporizers aren't accurate.
Here are some pointers to start your research:
- At what age is a human brain fully developed?
- What substance do I want to use and why?
- Is inhaling that substance X my only option, or are there healthier ways? (Yes, I made an assumption)
- Do I need a measuring device for X substance? (Volumetric for accuracy)
- How can I verify that the substance X isn't something else? (The same for the non refillable cartridge)
Note: If you have a refillable cartridge, you also have to think about what solvent to use for substance X and how to prepare it for vaping.