My writing is good, but I feel like it could be better. How can I make it more solid?
Make sure you are speaking in the active voice, instead of the passive voice. The active voice is where the subject of the sentence does the verb, instead of the verb happening to the subject. For example: Passive voice: The dog was hit by the car. Active voice: The car hit the dog. The active voice is much stronger and clearer to use.
I have a hard time studying for extended periods of time. How can I help this?
Try studying for 30 minutes at a time, and then taking a 5-10 minute break. During your study time, make sure there are no distractions - put your phone on silent or turn it off. During break periods, do something completely unrelated to school work - listen to music, make a sandwich, etc. You will be refreshed when you come back.
Why does weed impair your memory?
When a person smokes weed, it causes them to have fewer (if any) REM cycles when they sleep. REM cycles, short for Rapid Eye Movement cycles, are the parts of your sleep cycle where your brain forms memories. Fewer REM cycles means your brain's ability to create memories is impaired.