... dont wanna do Saturdays anymore but im not sure how this new job is going. Should i ask my new boss or just quit or just wait a few more weeks?
How long have you been on the new job? Are you on probation on the new job? If you are they will tell you how you are doing at the end of it. Usually they will give you feedback on how well you are doing. If you've been on the job a month you can ask how you are doing and is there anything you should improve on. Their answer should give uou the info you need.
I have ten years of work experiance in different countries and i have also done weekends and night shifts as well so my answer is stay in your new job and show your boss that your a good employee and after that it will be more easy to say it with out having any truble try to make it optional, like instead of saying you dont want to do weekends say can i please not work on weekends, but if it still does not works then search for another job and dont say anything untill you have found the job you want because if you dont love doing what your doing your going to lose most of the things you love.