Lose fat, not weight?

Hi there!

My name is Jessica, I'm 5'3, and weigh 118lb. Definitely a petite girl, as my bone structure is relatively small (small wrists and slender fingers). As a result, any excess fat on my body is quite visible and unattractive. While I'm far from being overweight, I hate seeing myself in a bikini or in a tank top, as my tummy and upper arms are soft and a lil jiggly. Skinny-fat, I suppose?

I'm a TOTAL BEGINNER in the fitness department, but I have made a serious commitment to a better, healthier lifestyle and physique. I am eating an extremely clean diet at maintenance level (1800cals). Can anyone offer some advice on losing FAT, rather than WEIGHT? I want to finally get the sexy, toned body of my dreams! Especially in the upper arms. I am currently laying off the cardio, as I don't want to risk losing any of my muscle mass... Yes I have visible biceps/triceps when I flex, but they don't seem to be doing much for my overall appearance. I am in possession of 5lb and 10lb dumbbells and the internet. Please help!

Thank you! :)