How can I fix my parent's papers?

You are able to petition your step brother and your parent when you turn 21. I need to know how your parent entered the US.

You will not be able to petition for your "immediate relative" parents until you are actually 21 (as you have indicated). The process at that time will entail filing a series of petitions by you as the US citizen "sponsor" on their behalf (with each of them as "Beneficiaries"). There are complications relating to this process, however, due to existing administrative "bars" under IIRAIRA Regulations and the fact that they appear to be undocumented (perhaps having entered without inspection) and may or may not qualify for existing "waivers" of inadmissibility. A detailed answer to your question would require much more detailed understanding of your and their particular circumstances. A consultation with an experienced immigration lawyer would be appropriate. Your half-brother, by blood, would follow a somewhat different process with you as the sponsor for a "sibling" and would involve a much longer waiting period (for visa availability) since "siblings" are not considered "immediate family" under the current Regulations and visa availability is therefore subject to availability under the quota system for that particular classification and based upon a "priority date" established by initial I-130 filings (after you are 21, again) for him. In the State of Mississippi, at this time, your parents are unable to process for a MS driver's license without proof of valid non-immigrant or immigrant status.

You have to wait till you turn 21 before you can petition for them. The manner in which they get their Green Cards would depend on whether or not they entered the country legally. If they entered the country legally and someone filed an application for Immigration benefits for them before April 2001, they would be able to "adjust status" in the U.S. itself without needing to go back to the home country; if not, they will need to leave (hopefully for a short time of no more than 2 months) and re-enter as Lawful Permanent Residents. You will need to file a form I-130 for them and provide proof of relationship via your Birth Certificate. You also need to know that you must show that you have the financial ability to support them (affidavit of support), and if, at 21, you are not earning enough, you will need to look for a co-sponsor. Please consult with an Immigration lawyer before you take any steps in this regard. The law is always changing and it is in your best interest and that of your parents that you take steps after having consulted with an attorney and preferably hired a good lawyer to help you through this.

First of all, explain whether your parents ENTERED the US lawfully or unlawfully. If they entered lawfully, you will be able to petition for them once you are 21 and they will be eligible to legalize their status within the US. If, however, they entered the US unlawfully, even when you turn 21, under the current immigration laws, your parents will NOT be able to legalize their status within the US. They would have to go back to their home country to consular process but as soon as they leave the US, they will trigger an automatic 10 year bar to reentry to the US because of their unlawful presence in the US and they will not be able to return to the US for 10 years unless they can prove extreme hardship to a US citizen spouse (impossible for them) get a waiver. As for your brother, you do not have to have the same last name but your birth certificate and his must show the same parents to establish that you are brother and sister and then you can petition for him. However, it takes about 10-12 years for a sibling of a US citizen petition to become current so it is still a long wait for your brother.

You are asking the right questions. When you are 21 you can sponsor your parents and your brother. A DWL will not be an issue. If they entered without permission, that will add a lot of complications to your case. My guess is the law will be very different in five years. But have a consult with a competent immigration attorney in your area who is an AILA member. Find out if your parents have 245i protection, U visa protection or any other option. This will make their life easier and may improve green card chances.