Not starting your gambling with the right mindset is already a wrong way to start gambling. You shouldn't think that you can't win or you won't win. What you should be thinking is that you're going to win but still as you think this, you should be realistic so that you don't make mistakes because when you aren't realistic, you'll be thinking you can do extraordinary things as winning millions of dollars with mere cents that you're using to gamble.
Although things like that can happen but they aren't common but happens once in a long time. First you should be looking for how you can make few profits and after you have gotten those then you can begin to aim higher. Having the right mindset is vital for all gamblers and can be the start of your profits or losing streaks while gambling.
I support the idea that in everything, in any new venture, you need to have a positive attitude. But I seriously doubt that a positive attitude alone will be enough to win big money in gambling. It all starts with the goals you set. If you are playing small bets with low odds then of course you should not be thinking about winning a million one day. You can try some slot games hoping to hit a jackpot for a small amount of money but I doubt that too. Most likely if you want to win big money in gambling you will need to risk big money, only this way something might actually work out.