Next take your first bold step.
Your follow up could look something like this:
*Talk to them in the hall or in class or wherever you notice them. If you're shy, it could like this: "Hi, how's it going? I think I've seen you around before. By the way, my name's .... What's yours?"
* Invite them to go for a hike OR play basketball OR whatever interests you that gives you time to get to know each other. Doesn't have to be radical. Fit them into your day naturally.
*As you get to know them, check in occasionally. It can be as simple as a text to see how they're doing.
*If they're neighbors, visit them.
*If they attend the same school, arrange to meet them for lunch or after class.
Choose one or two of these ideas at first or come up with ones of your own.
No rush. No pressure. Keep it real. At the same time, you're watching each interaction to see consistent behavior over time that models the qualities you admire.
How committed are you in following at least one of these suggestions?