To Whom Do We Give Tzedakah and Who Comes Before Whom?

Aseres Yemei Teshhuva between  Rosh hashana and yom kippur when many tzedaka requests are made by  Mosdos, Yeshivos individuals and organizations asking for donations as klal yisrael is in a giving mode of tzedaka during this time. we are bombarded by Tzedaka letters in the mail, robo calls, telemarketers soliciting donations, emails, a meshulach knocking at your door or approaching you in shul. Some have family obligations to support a relative.   
If one can afford to give to all that would be wonderful, however not everyone is capable of that.  The question is is whom do I have to give

According to Halacha there are priorities in who to give tzedaka to first. Please discuss this with your Local Rabbi as there are differences of opinions.
Some Poskim rule that Hachzokas hatorah is the highest form of giving tzedaka.  categories in giving based on the shulchan aruch Yore Deah: The Laws of Tzedakah siman 251

Category 1: Captives, prisoners and matters of life and death- pikuach nefesh
Category 2: Very close relatives


Category 3: Needy Torah scholars, support for dissemination of Torah learning, and other poor persons
Category 4: Communal needs
Category 5: To finance the cost of mitzvos
  Rav Moshe Feinstein rules (Igros Moshe Yore deah 144) that the giver of charity has the right of disposition and the system of detailed priorities applies only to communal Tzedaka funds. An individual has more leeway on the concept of Tovas hana'ah in giving. Some Poskim rule that Hachzokas hatorah is the highest form of giving tzedaka. see more about the halachos of Tzedaka HERE