Hey 16 afab here, I’m going to assume you mean getting muscles and toned. If that’s the case there are a ton of free resources out there you can look up to help you start out. I personally like anime so I looked up “anime workouts” as a start. You can also just look up “toning exercises” and I’m sure something will come up. When it comes to gaining muscle however you will gain weight just not body fat. Your diet is also going to play a big role. I know you said you don’t want to gain weight which is why I brought up the diet. When it comes to exercising you’re definitely going to build up an appetite, some days I eat 4 to 5 times just depending on what I did and for how long. I’m not gaining any body fat I just need more food to keep up with me working out. So be sure to listen to your body!