This is not the right place to this kind of subject and OP is just 15 year old kid he knows nothing the ins and out of gambling he is exposing himself to scammers by asking this kind of question and exposing his age, he needs guidance maybe his parents do not know that he is curios about gambling and this is bad, he could get himself to a lot of troubles at a very young age.
In recent years in my country and at forum I am looking that many young age guys under 18 have started to be more interested or want to gamble from an early age. This is really a warning for them and for their parents as well because sooner they get exposed to this and before they have started to earn money if they thin it is so easy to make money from it and if they get addicted this will have a very bad impact in their future studies and life as well. Here role of parents, guardians or all those who have young teens at home need to be extra cautious and keep a check about such things if they are involving themselves before the legal age is illegal and can face consequences of it.