I am young and got my first credit card a few months ago. I get 1% cashback, so I put all of my purchases on my credit card. I always pay it off a few days before the monthly deadline (or earlier if I'm getting close to the limit), so that I never carry a balance month to month. However, I am confused on what people mean by certain things.
1) 30% rule: I've heard that using more than 30% of available credit will impact your score negatively. However, some sources say that if you pay off the card, it does not impact anything. If I have a $1000 limit on my card, and I spend $800, but pay it back, will my credit score go down or up? I've also heard that you should try not to use more than 5% of credit, but then I wouldn't get cash back.
2) Would opening more cards help my score go up, or just keeping this one? Google says that it'll go down because of utilization ratio, but is mine 0 or 80% in this scenario?
3) Do I have to carry a small balance month to month to increase my credit score? That doesn't sound right but I've heard people say it.
Sorry if these are obvious questions, thanks!