How do you make friends?

Hello, I'm 16 years old (turning 17 this year). In the past few years, I've been struggling a lot with my mental health, dealing with severe depression. (I'm currently in therapy)

For the past month, I've been on summer break and I've been stuck in a cycle of severe isolation. I don't have friends to spend time with, and navigating this loneliness has been incredibly draining. While I am used to isolating myself for months, I genuinely want to break this pattern and learn how to build real life friendships, but I feel completely disconnected from people my age.

I see people my age hanging out, going on trips, and talking all the time. I've never been in an actual friend group, and honestly, I don't understand how people even do it.

How do you meet new people? How do you start a conversation out of nowhere? How do you transition from an acquaintance to a real friend?

I can't help but feel like I am the problem. Maybe I'm not appealing or interesting enough, but I still crave social interactions. I just want someone who genuinely cares about me, asks me to hang out, and is interested in my life.

I know I can't force people to be my friends, but I am completely stuck. I don't know what to do or how to change this situation.