you should be able to do the same things as a female character with sexism on, as a male character, it will just be much, much harder

omg thanks for the fast reply

In general, with sexism on it plays exactly like Native — you can do everything a male character can do, but you need higher base renown before you can do it, and sometimes the dialogue options will be misleading. For example, it takes around 750 renown as a female (with sexism on) to join a kingdom as a vassal and be awarded a fief; however, the king might still tell you that you won't get a fief (because to give a fief to a woman would make others think he is bewitched, which is the same response for when your renown is too low) even if you reach that value (when in fact you do gain one upon joining). For comparison's sake, it takes only 200 renown for a male (or a female with sexism off) to swear vassalage and be given a fief, and the dialogue with the king will clearly say you'll receive one. Once you are a vassal — with or without a fief given to you upon joining — you function exactly as a male lord would; you can become the Marshall, you can ask for more fiefs, you can break your oath and secede, etc.