The NRA has firearms safety classes and education, firearms training, donates to various clubs and organizations like the Boy Scouts of America, supports police training and donates money to ranges around the country. This is where NRA membership dues and donations are used.
The NRA-ILA is the Institute for Legislative Action it is a different organization with a different budget. NRA membership money and donations don't go to the NRA-ILA, because it is a lobbying organization. This is the part of the NRA with which some people seem to have a problem. NRA membership dues have nothing to do with this organization.
If the NRA-ILA and its work bothers you join another pro-2A group. Find one whose ideals you agree with, but join a group. As individuals we can write legislators, but we don't file lawsuits against local, state, and the federal government. As individuals we don't organize funds, provide lawyers, or get media spotlights put on cases of governmental abuse against gun owners.
Join a state or local organization of your choice, or start your own pro2A group if you feel none of the larger groups have your interest in mind. In New Jersey we have NJ2AS (New Jersey 2nd Amendment Society). They are a grassroots group that has started a recall attempt to rid New Jersey of the anti-gun president of the state senate. The ANJRPC (Assoc. of New Jersey Pistol and Rifle Clubs) has it's own program that is sending towns that don't comply with state laws in approving Firearms ID cards and pistol purchasing permits letters informing them that they are breaking the law. They are going to take these towns and cities to court where they will have to explain to a judge why they can't seem to comply with state laws.
There are great groups like SAF (Second Amendment Foundation) which has two dozen pro 2A court cases going at any one time.They were involved in U.S. Supreme Court cases D.C. Vs Heller and McDonald vs Chicago. Those two cases are the most important rulings in modern times regarding the right to bear arms. They could use your donations or you can join for $15 a year.
If you believe that the NRA-ILA compromises our rights away you can join the Gun Owner's of America. GOA's membership is $20 a year. They were called “ the only no-compromise gun lobby in Washington” by Ron Paul.
Lastly there is the JPFO (Jew for the Preservation of Firearms Ownership). Despite its name, this group is open to all people regardless of religion. This group also feels that the NRA-ILA is too willing to compromise on the 2nd Amendment, they are ardently against gun control. If you feel this group is more in line with your thinking you can be a member for $25 a year. There are pro-RTKBA (Right To Keep and Bear Arms) groups and organizations large and small in every state and they could all use your time and/or money to fight anti gunners inside and outside of our government.
Posting pro gun memes, pictures of you and your guns, sharing post/videos, calling yourself a sheepdog, or joining pro2A FaceBook groups doesn't make you a 2nd amendment activist, it makes you a 2nd amendment beneficiary. If all you do is cheer or criticize from the sidelines you are not helping the cause you claim to support. The existing groups that are fighting for our rights could use your help both with your time and your money. If you don't like any of the groups that you have found, you think the existing groups don't represent you, or you think that you can do better, then start your own organization. The entire point of advocacy can be summed up in one phrase.
DON'T TALK ABOUT IT, BE ABOUT IT!