Slimming down my thighs

I’m trying to slim down my thighs, mostly my inner thigh. I started to work out last night and I’ve been pretty sore today. Here’s my question, when you’re sore your body is building muscle since they’re torn. I don’t want to gain muscle at all i just want to slim my legs but since I’m sore am I just going to gain muscle and make them slightly more bulky? helppppp. Am I supposed to be sore? Will it still slim my legs?

Here’s what my thighs look like. I’m the one on the right