Only the ones with great skills and knowledge or great capitals in trading or with some popular websites or gambling websites can earn a living with bitcoin but not me and you who just earn bitcoin from signature campaigns or small trades.
It depends on what type of gambling they want to tackle with, if it is dice, plinko, or other easy method and doesn't need any technique or skill to play it a first time experience is enough to play it but for poker that needs to analyzed certain rules when playing poker, and actually in my opinion I would never go with gambling in the first place cause even in poker it is very unlikely risky!