Need little advise please

Hi,
I am 22 years old girl. I am 129 pounds rite now and trying to loss 15- 20 pounds. My height is 5 feet 1 inch. I recently starting gym and quite motivated to lose weight. I usually do eclectical for 30 mins and 15- 20 mins of stairmaster. And i am not so sure if i should do strength training and if so what kind because i dont want to have muscles, i only want to lose weight. I have started to watch for what i eat and trying to eat healthy. Please advise and help

Thanks