You don't. In gambling, everybody has only one level. There is really no point in getting a lot of experience in it as the changes are basically the same across the board.
So "leveling up" is basically a stupid concept in the world of gambling.
Exactly, if you have the mindset of leveling up right from the onset then I bet you'll never be successful at gambling. It can even land you in serious addiction if care is not taken so I will suggested you be as modest as possible before you gamble and never imagine leveling up.