How can I file papers for my mother and two brothers?

In order to file for your mother and siblings your first step is probably to inquire what happened to the initial petitions filed by your father, especially if your petitions for your brothers were also filed at the time. How you proceed will depend on the outcome of that inquiry. But with respect to your mother in particular, you can file a Form I-130 petition for alien relative with CIS. As an immediate relative of a US citizen [you] approval of that petition is currently taking about 8-10 months. Once approved, you will contact or be contacted by National Visa Center "NVC" for the next step which is to apply for na immigrant visa. The IV package including the forms; fees and I-864 affidavit of support will be sent to the US embassy in your mother's home country where she will be called to appear for immigrant [green card interview] You can simultaneously file for EACH one of your brothers as siblings of US relative [you] in the F4 family preference category. Petitions in that category often take a very long time and the earlier you file their petitions the better. This is why you need to inquire as to what happened to the earlier petitions filed for them, if any. They may have earlier priority dates or CSPA benefits and as such will have a much earlier time coming to the US.Finally, as a 21 year old, there may be issues regarding your ability to complete Form I-864 Affidavit of Support. If so, you need a co-sponsor able to undertake the financial obligations

You can petition for your mother and for your brothers but your mother will qualify for a visa within about 9-12 months whereas the wait for your brothers will be about 10-12 years. As far as your father's petition, you need to find out from him if he had ever received any correspondence from USCIS on his petition.