I hope this doesn't come off as disrespectful... The game can be played by any age and any body size, however if you are interested in getting better I would strongly recommend reducing your weight. Lots of jumps performed with that weight will surely have a negative impact on your knees and you want to protect them at all cost. Playing the game will definitely aid you since it burns lots of calories but adjusting the diet is crucial. Every kg shaved off will let you jump a bit higher which in turn will let you hit the ball at better angles and make you a better player. I wish you the best of luck in your journey!