I’m not sure if I should start GYM

OK so this is my body. my underwear is covering my sides.

I feel super insecure about my upper body but also I appreciate my boobs so im scared I’ll lose them if i start working out and dieting?

Edit:

I only had one month so i figured GYM wasn’t necessary so started exercising on my own.

I now swim early in the mornings and take walks. Thank you for all the lovely ladies in the comments for being extremely kind and helping. Love xx

(also please ignore my messiness and face.)