How to handle a shy guy?

You don’t “get” someone to open up. You can’t change someone else’s behavior to fit your whims.

When he feels ready, he will open up. Or he won’t. But it has to be HIS decision.

At age 20 he might well not be sure and confident of what he is doing. Pushing him too hard will blow up in your face.

DON’T rush him!!! YOU need to be your normal outgoing self & allow him to remain in HIS comfort zone of being shy. IF you can’t ACCEPT him JUST LIKE HE IS or NOT able to deal with his shyness, then you 2 should NOT be together!!! He’s still young & may well become less shy over time; but it should be in HIS OWN TIME!!! For now, I suggest you be satisfied with texting until he can grow out of his shyness!!!

I’m 40. I hate talking on the phone. It might not be being shy. Maybe he just hates talking on the phone.

I remember being 17 and my GF loved talking on the phone. I hated every second of it. We are talking five and six hours convos on the phone. And that was before cell phones. She lived five miles away so I was just thinking, “why don’t you drive over so we can smoke some weed and boob-play.” But she just loved talking on the phone.

It may be not shyness.
Some people simply feel awkward speaking into a device.
Leave gaps. Don’t fill every moment with chatter.
Don’t announce that you want him to talk more. Just pause from time to time.
When I was a teen, back when phones all had a long curly cord coming out of them, I had a boyfriend who was awkward about filling silences, sometimes in person too. My grandma gave me the same advice. I started listening to him breathe. I could close my eyes, and let the silence pull us together, like we were in the same room.
When I started giving him more time to put his thoughts together, he started talking more.
Don’t think of not talking as sending a blank text. Think of it as time you are not confusing the other person with incessant squeaks and drones.