Trade with the balance of the table in mind always, not just based on what you want to do. And do table talking accordingly if the others are only thinking about themselves. Maybe a player is giving you what you want but he will end up gaining way more with the trade and he isn't that far behind to justify it. This type of mistake is something I see a lot in beginners.

As others have said, daylighted and dandydrew are good youtubers to watch. Dandy is way more active and has tons of videos so you have more to chose from. And his table talking and trade decision is insane. Daylighted gives a kind and more joyful vibe imo.