Poor and starving people don’t rely on Instagram to get help from people on the other side of the planet. Scammers, however, do use the Internet to prey on people.
You can say a prayer for people you can’t help directly, for whatever reason-- “Dear God, please give him the graces you want to give him the most.” Or something like that.
But you’re currently not in a situation where you can be expected to financially help people directly, let alone random strangers who ask for things on the Internet.
Right now, your job is to be a student. If you have extra time, you can be active in structured organizations that are designed to help people— you can volunteer at a soup kitchen, or a nursing home, or Big Brothers/Big Sisters, or an animal shelter, or whatever fits with your schedule, your mobility, and your preferences. You can be generous with your time and altar serve, or read at Mass, or teach Sunday School, or whatever is appropriate for your skills/status. If you want to financially impact someone directly, you can see if your youth group wants to
Sponsor a Child ($360/year) or help
sponsor a seminarian or do fundraisers for one-off
community projects.
It’s good that you want to be charitable. But at this point, it’s probably best to keep your charity closest to home, by contributing your time and talent to places that would benefit them, and save up your treasure in anticipation of your own future needs.