There are alot of bodyweight exercises and jumping drills/sprint work that you can do with limited access to equipment. Your diet is going to play the biggest role in how much weight you gain along with you still growing at your current age. Make sure you get plenty of good, healthy foods that are high in protein, good fats, and complex carbohydrates. Avoid junk foods as much as possible, save room for the things that can actually help you improve.
With the pull up bar you should definitely take advantage of that, get GOOD at pull ups, it will help you in any sport you decide to play! Some other good bodyweight exercises are push ups, incline push ups, planks, walking lunges, lunges, reverse lunges, bulgarian splint squats, plank variations, sprints, jumps of all types, and line hops/rfi drills.
To make this into a workout template you can start with a dynamic warm up, do a few sets of line hops, do a few sets of short sprints and jumps (standing jumps, running jumps, broad jumps, low intensity bounding variations). Then pick one upper body PUSHING movement (push up of some type or dip) do 3-4 sets, one upper body PULLING movement (pull up or chin up) do 3-4 sets, and one or two lower body movements and do 3-4 sets, and one plank variation (all fours, one arm one leg, etc.)and do 2-3 sets. Make sure to take a day off in between strength training sessions and always warm up thoroughly. You can do alot right now with what you have access to that will help prepare you for more intesive exercises and drills later on.
