Believing in yourself and that you can accomplish anything you put your mind to is a great feeling because if you are passionate enough to try something then you are capable of succeeding. It’s just the question of are you willing to put everything into something you care about. Honestly if you have enough commitment to start something then just go full steam ahead with it.
Never feel like you aren’t capable of succeeding because if that’s what is running through your mind then to be honest yes you will probably fail. All the advice i can give you is “never look back never think twice” once you’ve got an idea in your head that you like write it down and yes maybe keeping thinking until you have some ideas because maybe the first idea that comes into your mind may not be fully thought through.
Possibly just a random idea you’ve had that you think oh yea this will work for definite. I had so many ideas i thought would be good and after i tried them a lot of them yes failed but then i had the idea of starting a blog to help other people who’ve gone through the same as me or are in the process of it. Once i started it i put all my time into it sat with a laptop in front of me and a pen and pad of paper writing ideas what to write about.
Sometimes i could spend a while brainstorming and sat thinking about what to write and how to word things and what to even write in the first place but i never gave up on the idea of helping other people because that was my goal and i wasn’t going to stop until i have accomplished it.