For catholics?

why can't women become priests (why only nuns). why do you have to talk to a pries to forgive your sins, cant god do that, why fast during lint (and don't tell me because Jesus did. Jesus died on a cross too are you gonna do that). where in the bible dose it say that pergatory exists or did you guys just make that up.......I have herd several answers for these questions and none of them are real answers like the first one God mad men and women for different things well how do you guys know what god made us for isn't that the mysterie of life.......I mean all of this respectfully.....but most of my friends and family are catholic and none of them can explain these questions........I can't believe unless I understand what to believe