Let me add a few thoughts here because I'm a fitness junky after having gradually becoming extremely chunky over the years of having done nothing to avoid it. I have noticed that a number of fat and really unfit types show up at the gym, most especially after the New Year's celebration. They get on the equipment and go like a bat out of hell, work up a huge sweat and leave. This goes on for a week or three and you never see them again. It's because they think that a really hot workout for three weeks will undo what years of gluttony and being a couch potato will undo and they get disappointed and quit.
My best advice is to take it slow, use light weights with lots of repetitions which will result in toning, spend half the gym time doing cardio. Eat a light low fat, low carb salt and sugar free diet keeping around 1200 -1300 calories a day and take a brisk walk later in the day. Don't forget to drink plenty of water. If you are on a T blocker or have had an orchiectomy the the small amount of testosterone produced by the adrenal gland isn't going to affect your feminizing program adversely in any way. We need a small amount of T just like cis women do in order to have any libido whatsoever.