What kind of sports suit me?

My main purpose is to restore my self-confidence.

I want to feel strong, maybe a little intimidating only to prevent possible future frictions, fights, bullies...

I'd like to have confidence that I'm able to defend myself and attack if nessesary.

I'm in doubt between martial arts(kung fu maybe?) and hitting gym(body-building)

I guess both fulfill my main purpose of feeling confidence and strength,yet I'd like to get your opinion and advice too since I almost never have exersised seriously and don't know what sport fulfill which purpose.

 

First of all thanks for your comments. Good to get advice
But Guys I forgot to say I got slight injuries. In shoulder and knee. I'm not comfortable throwing punches as there is an anomaly in the shoulder tendon( Restrictions in movement). Knee gets hurt after lengthy walks( I think its inflammatory)

Am I still able to do martial arts? Or is it better to lift light weights and make the muscles stronger first?

 

You want to tell what that means? Also why not kung fu? I'm not sure if jujitsu is practiced in my place