You should steer clear of creating yourself a rule to say that you need to link out at least once to an external source on every page of your website. On some of your pages, multiple outbound links to great resources can be fine. On other pages, it might not make sense to link out.
If an outbound link adds value to your website visitors, then it's a good thing to do. If it doesn't, don't do it. It really shouldn't be any more complicated than that.
Linking to (or not linking to) your social media profiles will have absolutely zero impact on your SEO, but could be useful for your audience.
I'm not sure what industry you are in but a government white paper should be a superb resource to link to if you think it adds value.
