Guy's Behavior

How to tell a guy is genuinely into me, or just being friendly or can be deemed as a bit weird?

So there’s this guy at my job who I met like 1 or 2 weeks ago. He seems nice but I wonder if there’s something more to him. He manages to talk to me everyday and every second he sees me. He also ask one of the girls I talk to at work about me quite a bit. She told me he ask what station I am working at. He asked her one day when I didn’t show up but I was on the schedule. He was like why I wasn’t there when it says I worked. He even mentioned the exact days I worked to me so I think he had a very good idea. But the weird thing is how he remembered my name the 2nd day we talked but a few days later he didn’t remember my name when he was asking my friend about me. But he was able to know my schedule. Another thing is he makes a lot of eye contact with me when I talk. Sometimes it’s too much where I end up looking away. But I think that’s normal when talking. We also had a lot in common. But I also read that narcissists can make a lot of eye contact. So it had me thinking is there something more to him. I hope someone can provide some insight or maybe I could just be overthinking everything. Should I be concern about him?
How to tell a guy is genuinely into me, or just being friendly or can be deemed as a bit weird?
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