I want to gain personality because i am so thin.so help me to gain weight?

Lifestyle change: This is a great plan. There's more than this to learning to work well and be appropriately assertive with people, but getting lean muscle will help you in many ways. Resistance-train in the gym and work on making friendships with accomplished guys. Aerobic work for definition. Avoid steroids, but creatine and an electronic muscle stimulator (till it hurts if your dr ok's) are worth trying.