It can take awhile to make friends in ballroom. It is going to depend on your studio or venue. I come from a really competitive studio and so everyone there is guarded for at least ten months...and even some after that. If their focus is comp then you have to go to comp with them because much of the bonding happens there.

Make sure you aren't correcting anyone when you dance. It can be easy to not even realize you are doing it but I promise you when someone who isn't a very good dancer makes a mistake and blames it on me I will never dance with them again. Chances are I'll be polite but I don't want to be friends with someone who wastes my free time criticizing me. If somone makes a legitimate point and does it nicely I don't mind that with the understanding that we are friends already or you're a damned good dancer and you are right. If these criterion are not met I promise you that you are coming off as arrogant.

I'm not saying you do this...I'm saying a lot of people do this and no one ever tells someone to their face what bad dance etiquette this is but it should be covered EVERY time in EVERY group lesson.