hi! i’m a bit new to this so i’m sorry haha. but! i’ve recently felt the need to fast. i’m planning on doing a one meal a day fast to start off. i was wondering how i fast? for example, do i pray the entire day or can i go out and do stuff? again, i’m sorry i’m really new to this. also! school is starting soon and i was wondering if i could also do it during school. thank you!!!
Let me first roll out the welcome mat for you.

There are precious few young people who are active on this forum, so I'm always happy when someone new joins! I haven't been here often recently due to school and other priorities but I do try to pop in.
If you decide on fasting from food I really encourage you to do so prior to the new school year beginning, and only for a short duration. It's the quality of the experience, which will hopefully be edifying and draw you closer to God, rather than the quantity of time that is the most crucial to deriving benefit. You want to begin the new school year spiritually, physically, mentally, and emotionally rejuvenated so that you can build a strong foundation. First impressions matter, and you want to make sure you are presenting your best self to your new teachers and classmates. When you fast, it causes physical changes to your body that can then alter how well you function mentally. I feel fuzzy brained, less able to remember details, less quick to come up with solutions to problems, less capable of contributing meaningfully to class discussions. It kicks down my immune system so I am much more vulnerable to picking up a cold that will then cause me to have to miss out. I feel much more sensitive, and like I'm in danger of my emotions controlling me than me controlling my emotions. I have to fast from food relatively often for medical reasons, but do try to make a silver lining in it by making it into a spiritual experience. A single day can be sufficient for accomplishing that goal.
At 16 most girls have already gone through their most rapid growth spurts, so fasting isn't as detrimental in that regard, but you could be a slow bloomer like I am. I've grown taller in the past year, and I'm in college.

Fasting also impacts adolescent girls in a hormonal way that is very different from how it effects adults and boys. There have been medical studies on young Muslim women who fast during the month of Ramadan to study how that impacts their bodies during that time and afterwards. They do not entirely abstain from food during this time, but restrict their eating to only after the sun has set every evening. It causes a repeated cycle of fasting and refeeding that is taxing on their body. Your cycle regularity is controlled by this axis between your ovaries, pituitary, and hypothalamus, and fasting sort of spins that axis around, which can wreak havoc. The studies showed that young women who fasted during Ramadan were substantially more at risk for suffering from menstrual dysfunction, which does not just immediately resolve itself once the fast is broken. It's also not just confined to.....
that direct issue, but also other unpleasant things like sleep disruption, painful hormonal cystic acne breakouts, metabolism issues, severer cramping.
You can fast in other meaningful ways beside refraining from food. The same objective can be achieved by giving up something else that serves as a form of sustenance or pleasure for your life and instead dedicating that time to being in communion with God. I've done social media fasts and music fasts, spending the time I would have been online or listening to music reading scripture or in prayer.
Edit: I hadn't read the post above about how your parents aren't letting you fast when I wrote this post in response to the OP. It's still applicable. When you're 18 you're still going to be more physically sensitive to fasting than older women, but you can still fast through other methods than by abstaining from food.
