You need to plan first.

In this story you will start as a practitioner of magic in a fantasy world, who due to a large ritual involving large amounts of magic that has failed you have turned into a horny well hung Futa who will have sex on your mind quite often, you release pheromones that make most things near you horny and your cum has the property of making those who come into contact with it horny, those who drink it or take it into their vagina or asshole will become willing and loyal sex slaves who will do anything please you, their new mistress. Perhaps after a long time of taking your cum they might grow a dick of their own or turn more feminine and sprout a pair of breasts. So either you journey forth and fuck your way across the world or perhaps find a lair and pray upon the unsuspecting because there's one thing you can be sure of, people may or may not try and hunt you down, why will they try and hunt you down? Slavers are always looking for exotic slaves, mages always looking for new things to research or maybe a powerful Noble with certain fetishes may desire you as a loyal fuck toy- *COUGH* servant I mean.