New to CSGO problem

Competitive is exactly what it is called, people don't like to lose matches because it ruins their elo and ranking. When people feel that someone on their team is bringing them down, they will kick you because they believe they can get more use out of a bot. I'd recommend playing more casual and unranked matches to work on your gamesense and other skills, and then next time you play competitive, you will be a lot more reliable, and teams would be willing to keep you. Also, if you're playing for free or have a low trust factor, you might run into a lot of griefers who try to kick people for fun.