If the situation is as you mentioned, it is Haram (prohibited) for you
to work in a casino, because it involves cooperation in sin and transgression. It is also prohibited to accept tips from those who frequent the casino. The salary you earn out of this is also Haram. It is obligatory on you to leave this job and dispose of the ill-gotten money you received as a salary or tips. We ask Allah to compensate you with a Halal (lawful) substitute that is better than this and to help you get married with Halal money instead of this Haram wealth. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.