My mom wants me to take karate,but I dont want to because Im scared of fighting.?

My mom wants me to take Karate because she saw a nice Karate dojo and was wowed by the training techniques they did there. Now she wants me to join that place. I want to go kind of because its a good workout and alot of my friends lost weight because of Karate or tae kwon do. But on the other hand,Im scared. Im scared that I will have trouble finding friends,Im scared of fighting/sparring. Im not a wimp,if someone messes with me,I will beat the heck out of them. Im scared of fighting in martial arts.