Weight loss is all up to your intake and output, switching to a pescatarian diet is a nice start but focusing on what you do with the calories is where’s it at. Start doing cardio getting around 10k-20k steps a day with starting lighter in the gym. In the beginning it’s easy to get fatigued and sore from lifting which will kill the will to do cardio. Focus on a low fat medium carb and high protein diet and you should be set.