I (22F) don’t understand my work crush (22M) situation/don’t know what to do

Hello, I don’t often look for help but I have a situation with a guy at my workplace.
It’s making me stress and struggle to work properly.

I’m working in a building with a lot of companies.
The “only” real place where all the different companies reunite is at the cafeteria, at lunchtime.
So, ever since I got into this company, during lunchtime, this guy has always been staring at me, at EVERY lunch, but I didn’t care.
I don’t know him, he’s not in the same company as mine.
Over time, I started to look at him back, very quickly, never directly into his eyes.
Physically speaking, he’s my type, plus he seems nice and he’s doing an interesting job. (we’re both interns)

Last week, it started to become obvious that he was staring at me and looking for me (we were sitting at a table and he basically turned his head 360 degrees to look at me lol), so I asked my work wife to confirm that and she stated that he really stares at me + not in a discreet way. I thought it was in my head and needed confirmation.

I digged deeper to know this guy’s name, job, etc. (he probably doesn’t even know my first name). I got all of his social media, we have a friend in common, etc.
BUT we have a group chat with all of the companies so he can easily find me ’cause I put my face as my profile picture. He never reached/texted me.
I don’t want to make the first move because I do this all the time and it’s exhausting me. For once, I would like to be talked to.

Twice, I got out of the building early and he got out almost at the same time, saw me, but rushed out of the building (almost running to idk where). Like I never existed/ like he didn’t care about me.

Yesterday, I was alone at a table at lunch and he was having lunch with his colleagues at the table next to mine; as usual, he looked at me multiple times and I tried to look back, but my heart is always rushing/I’m stressing out and I can’t smile or even look at him in his eyes (seems like love / lovesick lol). at the end of their lunch, he even stood up almost next to me, looking a me maybe waiting for me to look at him back, but I didn’t. I was looking as his feet…
Also I noticed that some of his colleagues look at me too, maybe they noticed something. (and when it comes to them, I manage to look at them in their eyes…haha).
I got out of the building at the same time as him and ended up in the metro with him, I kind of smiled / made a weird face with my brows to say “hey I’m here you know you can like talk to me” but he just didn’t do anything. He wasn’t that close to me tho and there was a lot of people.

Also, I have a very “resting b face”, I don’t smile a lot, my body language is terrible even if I want to smile at him, he may be thinking I’m not interested. But I clearly am.

I need advice on what you think of the situation and what to do…
I’m terrible at understanding others/analyzing body language and basic things.
If someone is great at analyzing body langage/men/ etc, please!

My questions are:

– Why does he stare at me in public and missed 3 times the chance to talk to me when we were alone/outside?

– What does this guy want? (maybe a GUY can reply to this?)

– What should I do if I want us to talk it out? Should I add him on social media even if this is showing that I looked it up, know his name and everything?

huge THANKS to anyone who helps me on this!

TL;DR: I have a crush at my workplace (I don’t work with him, it’s not the same company) who stares at me during lunchtime everyday, but I’m too shy/stressed to look at him back, it’s been like this for months, we met outstide the workplace but he never talked to me. I want to know what he wants, what can be done to move from this situation, but I don’t want to make the first move (but since it’s driving me crazy, maybe I will if it’s the only way to find all of the answers)