At this stage of not knowing what you want...best thing would be to get to a good sax shop with lots to choose between, somewere like sax.co seek trere advice and try lots until you hit on the right one....good look..
Firstly what size of tip opening you are best suited to playing. Generally the more experienced you are the larger the tip opening that you can play. The larger the opening the more air you can put into the sax, and often the louder/more expressive the sound that you can produce.
Secondly it depends what sort ofsound that you want to produce - bright or dark, edgy or mellow, more vintage/more contemporary,
and so on. Do you currently play, and what mouthpiece do you currently use? Finding the right mouthpiece is not an exact science but we can make progress by getting a sense of the sort of sound you want to produce and/or what you don't like about your current mouthpiece.
So any additional info that you can give us will help us narrow down some suggestions.
Hope this helps.