This would be a good place to start if you’re curious about the mission statement of the UN. This website has a lot of good information about their areas of focus. https://www.un.org/en/our-work
The work of the UN focuses on five major areas. 1.Maintain International Peace and Security. 2.Protect Human Rights. 3.Deliver Humanitarian Aid. 3.Support Sustainable Development and Climate Action. 3.Uphold International Law
They have a lot of information on their website about all of these areas. I would highly suggest going and looking at information on their peacekeeping and how they’ve helped in that area. They are certainly far from perfect but that doesn’t make them pointless. They do a lot of good work and are making a net positive impact.
It’s probably true that some of the countries that are members of the UN use that to spread misinformation and/or keeping the UN from doing a more effective job. However, to state that that’s the only thing the UN does is In my opinion is completely inaccurate. You’re welcome to look at my comments further up or go to the UN website yourself and see all the different areas that they make an impact in. Like I had said in another comment just because they aren’t perfect doesn’t mean they’re pointless. You’re welcome to come to your own conclusions, but I feel that the UN is a net positive in this world. I think it’s better to have the UN and actually work on improving it than to not have it at all.