The point is that what you think is true might not necessarily be true. So only reading things you like and believe to be accurate could mean you’re getting the truth, but it could also mean you’re getting a feedback loop of misinformation and indoctrination.
No clue. I try not to have a fixed opinion on news stories as they come out, but do try to read books, articles, and news about particular topics and the history leading up to them. Then, sometimes, that coalesces into an actual, informed opinion – but on a few topics.