How do i have certain

So i have been questioning my gender the entire year by now(finally decided to “hear” myself after years)and i am practically certain by now that i am trans but like there is something telling me i am not and cannot be trans cause i am too young to have certain and i can tolerate being a guy and the feelings that come with it(want to be a woman and hating being a guy and every caracteristic about it) or that i just got influenced by the internet into believing that i am trans, so because of that i came here asking if there is a way of having certain?.(sorry if it’s not the right place to post it and also for the bad english it’s not my native language)