Could someone help me with my daily goals?

So up until now I've been eating about 1200 calories a day.. sometimes over and sometimes under. I've lost weight, but now I'm scared that I'll lose the little muscle mass that I have :laugh: I don't think I need to weigh less, but I'd like to be stronger and leaner.

I'm 5'3'' and I weigh now about 117lbs. My work is standing up and sitting down, not much walking. I'm a lazy *kitten* and at home I spend most of my time yet again sitting. Here on my computer. For now I've had one cardio/strength train hour per week, and I've done some light weight 'lifts' at home (with 10lbs dumbbells). However, I want to start moving more, like doing some short running or walking, but also I'd love to start lifting heavy at the local gym.

So what do you think? How much should I eat? And how much protein?