One of the ways Russia influences American media is by influencing alternative American media such as Zero Hedge and The Daily Sheeple. This is because "even non-mainstream online news websites, like Zero Hedge, have been shown to influence the agenda of traditional mainstream news outlets. By doing this, for one example, they could spread misinformation about vaccines on non-mainstream media that could affect mainstream media especially when gullible people believe it and now there are more people to relay this misinformation. (Source 1)
Another way Russian misinformation works is by "confirming" people's beliefs, mostly by using social media. If a person believes something is happening in the world and sees something related or even of the actual thing happening, it can set off strong feelings toward the subject or people not on their side on the subject. One actual example of this actually happening was in 2017 when a legitimate looking group on facebook called Blacktivist posted videos of police brutality, and many people had joined it. It was later discovered that it was linked to Russia, and not at all a BLM group, and so it was taken down. The actual point of the group was to lure in people who mistrusted police and/or were worried about civil rights. This was so that it would make those people feel very strong feelings against police and maybe put distrust in the government for not doing much about it. The end result, which was what Russia wanted, was to cause division in American society.
The main aim of most of these misinformation campaigns can be a little confusing sometimes. Sometimes the aim could be to put distrust in authority figures, or in a new technology like 5G, or things like that. However, in the end, most of them are done to confuse and divide American citizens and in general make a situation somehow profit Russia.