17F] Does my cousin’s friend (18M) like me or is he just being nice?

I (17F) joined the school where my elder cousin brother (18M) studies. I ride in the same car as him and his friend (18M). When I first joined, his friend was the first one to talk to me — other than my cousin.

At first, we only talked in the car when we were alone. He wouldn’t really talk if my cousin or his sister (18F) was there. But now, in the new school year, he talks to me more often, and even when others are around sometimes.

He always smiles when he sees me — but I noticed he doesn’t really smile the same way when girl classmates come to talk to him. I’m not 100% sure, just something I noticed.

Once, he wished me good luck (when no one else was around), and then congratulated me after I won something. He even shook my hand, and that was actually in front of his sister. It just made me wonder — is that normal?

I don’t know if he’s just being nice because I’m younger, or if he actually likes me. I’m not sure what to do or think, and I tend to overthink a lot. Does it sound like he likes me? Or am I reading too much into it?