No real friends at 15?

I'm 15 and I don't really have any friends. At school I have a few "friends" if you can call them that. They always talk stupid things about me behind my back and you just can't trust them. They meet 1 minute away from my house and don't even ask if I might want to go out too. I don't know if that's expected too much, but it just makes me sad and I don't find real friends doing that. Outside of school I only have one "girlfriend" but we never write and never meet. I know, now you probably think like "Huh girlfriend?" But we only have phases where we meet. Then I have some contact with a boy who does not live near me and we have never met. But he's always there for me and we get along great. But then not more… Well, I don't really have girlfriends with whom you spend the night or meet spontaneously and go to McDonalds and I miss that. I always see all the girls in their stories with their friends and how they do everything and I always sit at home alone and watch Netflix all day.

I feel like an outsider. Are there any possibilities?

During the time you go to school you only find typical "school friends".

so people you call your friends just so you have someone, but who you will never see again after you graduate

I think the only way is to try to get to know people, e.g. Join clubs,. Just going out into the world and looking for hobbies and doing your thing brings a lot, but of course this is difficult at the moment and overall no instructions to find friends. I think at your age it is not at all unusual to have hardly any close people around you, since many friendships serve to not be alone… Which is okay, though. The best thing to do is to take care of what interests you a little and you will get to know people who are interested in the same thing.

First of all: wow, I'm really sorry for you - feel like you are hugged tightly by me, yes?
In fact, I have two tips: go to the outsiders in your class (no matter how weird they are) and hang out with them. Get involved with their interests and get involved.
My second tip is rather creepy: you said you have Instagram. Just enter your area of residence at Location above and see who is your age. Write to the person (preferably someone of the same sex or else the person thinks you are just a bot). If you get along you can meet and then you have a friendship outside of school 😊

Okay, that might sound stupid now, but it doesn't matter:

So: I think nine times that you can't and shouldn't force friendship, and that you still get to know real friends, that just happens. But not by watching netflix all day, go outside, that's where life lies.

You're not alone.

You will be able to recognize good friends really well. And friendships can't be forced