Looking at your texts I have the feeling you're very young? Doesn't matter tho, ill throw some maturity in your text.
Me: I have some good new, and some bad ones. Which one do you want to hear first?
Her: Bad news?
Till here you're doing ok..
Me: I wont be able to go, i completely forgot it was a friedns bday and he invited me to his house. and you told me a little late (it was 11:15pm) you should've said something before.
Here, I would've said something like"Im not gonna make it, I forgot I had a friends birthday, but have fun and thanks for inviting me
"
You were mad at her for not inviting you before, and now she did, so you should reward her with a thank you and it will make her invite you more, because you make her feel good about it. What you did is blame her for not contacting you earlier, which is making her feel bad, shouldn't do that. An alpha male never gets caught up in tiny stuff like letting people know shit on time, you make your own agenda.
Her: ohhh well sorry:(
5 min after
Her: and whats the good news?
You did good here, she shows a little interest by asking after 5 mins instead of ignoring.
Me: Next week for sure well hang out
Say something like, "Even tho I can't make it friday, I do have some time next week for you so we'll hang out, I'll text you later about it."
Her: haha okay
That way she'll be like okay, and expecting a text. The way you did it now, increases the chances that she'll flake.
good luck and if you have more questions, ask.