She invited me and I said no. Should I ask her out again?

Why not? The worst that can happen is that she will tell you some form of "Buzz off".

I'd say no because of this.

She was pretty I didn't make a move, I was too slow.
So you asked her again, to make a move and she made a no show.
Then you met again and you decided not to be slow this time and was rejected.
But she's interested, as she invites you somewhere the next day and you say no.

Now, as you have no dates at all and it's a party, a month has gone by and you want to invite her (not ask her out) it's for your own needs only.

So, no.

Thanks for the answer.
But everything we do is for our own needs. We date other people for ourselves.
I don´t really see the point here.

Thanks again

There was a wee message in my message

She wanted to feel respected and that you liked her for her....

And, I disagree something we do for our own needs, other things we do for others and some things we do jointly in life. We date because it's our nature to be within a relationship and have a companion yes, but ultimately that companion is worth something yes? And, it progresses to "togetherness"...

I see my point but that's ok.

are you sure she wanted something to happen?

after ^ she cancelled a date and then pushed you away when you tried to kiss her on your second actual date

maybe she'd like to become friends with you before deciding whether she wants to be in a relationship with you that involves kissing or anything else

if you're good with the idea of being her friend, and not planning to push her sexual boundaries, I'd say ask her to the party

you may become friends

you may remain as friends

or you may both decide that there's a possibility of a relationship

spend some time with her and get to know her - if you'd like to have her as a friend (and maybe more later)