You are allowed to make your own choices in life, even if that involves the unfortunate decision to harm your brain for a fleeting moment of pleasure and disconnection from reality.
You can find numerous texts related to this topic by utilizing the search function on the forum.
To put it briefly, smoking weed can harm your cognitive functions, resulting in issues such as memory loss, difficulty concentrating, and decreased problem-solving abilities. These effects can contribute to personality changes, and over time, may lead to depression and psychosis. Additionally, smoking weed can obviously cause damage to your lungs.
Moreover, being under the influence of drugs can make your mind and soul vulnerable to negative influences that surround you. It can impair your autonomy, essentially turning you into a slave, which is why the enemy promotes it so much. This is the opposite of what you should strive for.
So while you are free to do as you please, you should make an effort to detach from this negative and self-destructive behavior. There are several methods listed in the forum, from people who successfully quit smoking.