Others have responded to you in various ways. I'll try to add a little to the three points quoted above.
First, I was raised in a fatherless home. If not for my military experience I would know little about firearms. As of today I have no firearms due to an unfortunate boating accident; but I can assure you that it was a very large boat.
I encourage you to track down somebody in your circle of friends who is a gun owner and who can educate you about this and make sure that you are prepared to carry out your militia duty. More about this below.
Secondly, I will address the problem with "banning assault weapons". As others have pointed out, the definition is ever-changing because the actual goal of banning weapons is DISARMAMENT.
Here in the People's Republik of Kalifornia we have had three different "assault weapons" ban laws. It took three tries because the liberals are so ignorant that they were unable to even define what it was they wanted to ban.
One law outlawed a specific list of "assault weapons". I have been told that the process used by the anti-gun legislators was to go through gun catalogs and include on the list all black, scary, military-looking guns. This list included rifles, handguns, and shotguns.
As it became apparent that there were many more manufacturers of black, scary, military-looking guns than the tyrants ever imagined, they passed another law which outlawed "AR-series" rifles and "AK-series" rifles and authorized the Attorney General to add specific models as he saw fit. This law was struck down as unConstitutionally vague and the legislature eventually repealed the authority to add specific models to the banned list.
The third "assault weapons" law banned any center-fire rifle which had any two of the following: ability to accept detachable magazines; a pistol grip; flash suppressor; folding stock; or any of several other insignificant features.
For the most part, existing owners had 90 days after the passage of each law to register their "assault weapons". Such weapons then had to be treated as special items and transported as if they were concealable weapons. (Let's not get into that.)
For some of us, who have no intention of EVER registering a gun which we already own and who have no intention of giving up ownership of a weapon we already own, we could choose to modify the rifle to comply with the silly law or store the rifle out-of-state. I did some of both.
Feinstein's proposal is basically to implement nationwide the same nonsense that has been implemented in Kalifornia, by addressing magazine-fed rifles only and by not allowing ANY of the insignificant features. She also wants to ban magazines that hold more than 10 cartridges.
To answer your question, "What is the problem with banning assault weapons", the answer is that "assault weapons" are anything that people own that anti-gunners don't like. That is, ANYTHING AT ALL.
The farce is particularly well-illustrated by considering the Ruger Mini-14, some models of which are called "Ranch Rifles". Ranchers who need to protect their stock from predation by coyotes and other critters, need a light-weight rifle using an intermediate caliber cartridge and capable of firing many rounds in very rapid succession.
Coyotes typically operate in groups and they scatter quickly when the firing starts. The Rancher wants to eliminate as many as possible before they can run away.
The "Ranch Rifle" fires the same cartridge (.223) from the same length barrels having the same muzzle energy as that cartridge when fired from an AR-15. The Ranch Rifle can be equipped with magazines holding thirty cartridges or more, just like an AR-15.
What do you think are the chances that DiFi and her ilk will move to outlaw "Ranch Rifles" when the NEW and IMPROVED "Assault Weapons Ban" fails to have the effect of creating Utopia? I think the chances are 100%. Of this I am quite certain. Liberals will ban whatever the courts will permit.
Finally, a few words about the Second Amendment.
In April of 1775, Boston had been occupied for some time by THEIR OWN GOVERNMENT'S ARMY. This was as punishment for, among other things, destroying tea stored aboard ship in Boston Harbor on which no taxes had yet been paid.
The occupying Army had already engaged in disarmament measures in and around Boston, including barring the taking of longarms out of Boston and the confiscation of powder from facilities maintained by the colonists.
On April 19th of that year, the Army marched on Lexington and Concord to continue their program of disarming the colonists. The Minutemen, whose role was to respond to such outrages immediately, took up arms after being warned by Paul Revere and others that "the Regulars are coming out!"
Note that the warning was not, "The British are coming". All of the colonists were British subjects at the time. It was their own army that was being used against them.
Before the day was out, the army got its butt kicked by the colonists and retreated to Boston. The colonists then proceeded to lay siege to Boston. The Battle of Bunker Hill was a "victory" for the army in chasing the colonists away from some of the hills surrounding Boston. But the losses were great and sent the message that the task of disarming the colonists was not going to be easy.
Some time later, the colonists sent groups to take Fort Ticonderoga by force and bring back the cannon there to use against the army occupying Boston and the navy whose ships were in Boston Harbor. Note that the colonists were defying their own government in attacking Fort Ticonderoga.
In a masterful way, the colonists dragged the cannon cross-country and mounted them on the hills over-looking Boston and Boston Harbor in a single night. The occupying forces found themselves completely out-gunned in the morning. A deal was evidently struck that the occupiers would leave and not burn the city.
The Second Amendment was an enumeration of the right of Americans to keep and bear arms for defense of self, family, community, and country. Our Founders regretted that the people found themselves so helpless at the outbreak of hostilities against their own tyrannical government, as described in the Declaration of Independence. The arms they intended to protect included "every terrible instrument of the soldier" and most certainly included the cannon used to free Boston from occupation.
I got a lot of responses from all of you — some of them quite lengthy, and they were all interesting. Thank you, and I especially thank you that most of you did not accuse me of being a “liberal”, which I am NOT. I obviously have a lot to learn, and I got some direction from some of you for where to look to educate myself. I never paid much attention to this issue before. Guess I’d better start.
And some of you have served our country as part of our military. Thank you all for your service.