The Second Amendment is clear and decided. "The right to keep and bear arms shall not be infringed."
It does not say anything about registration, training, mental health status, gender, permits, fees, or how many. It is not a matter of opinion and is not up for a vote.
The Georgia Supreme Court made it perfectly clear what this means:
"The right of the whole people, old and young, men, women and boys, and not militia only, to keep and bear arms of every description, and not such merely as are used by the militia, shall not be infringed, curtailed, or broken in upon in the smallest degree..." ~ Nunn v. State of Georgia, (1846)
In Caetano v. Massachusetts (2016), the Supreme Court reiterated its earlier rulings that "the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding" and that its protection is not limited to "only those weapons useful in warfare".
"A law repugnant to the Constitution is void. An act of Congress repugnant to the Constitution cannot become a law. The Constitution supersedes all other laws, and the individual's rights shall be liberally enforced in favor of him, the clearly intended and expressly designated beneficiary." ~ Marbury v. Madison, (1803)
"Where rights secured by the Constitution are involved, there can be no rulemaking or legislation which would abrogate them". ~ Miranda v. Arizona (1966)
"An unconstitutional act is not a law; it confers no rights; it imposes no duties; it affords no protection; it creates no office; it is in legal contemplation as inoperative as though it had never been passed". ~ Norton v. Shelby County, Tennessee (1886)
"No state shall convert a liberty into a license, and charge a fee therefore."
~ Murdock v. Pennsylvania (1943)
"If the state converts a right (liberty) into a privilege, the citizen can ignore the license and fee and engage in the right (liberty) with impunity."
~ Shuttlesworth v. City of Birmingham, Alabama (1969)
Rights are like muscles. If they are not exercised regularly, you can lose them. The amendment does not require anyone to possess arms who is opposed to doing so. It merely specifies that the right to choose shall not be limited or restricted in any way. The right to self-defense is absolute. No one has the authority to restrict how you protect yourself.
The one exception is that a proper court of law may impose restrictions after due process. A convicted felon can have rights restricted as part of their sentence.