I noticed a post that seemed as if you had PM'ed some members and had been ignored.
It was hard to read and understand, as you used internet shorthand and didn't actually use sentences.
May I suggest that a good way to get to know people, rather than through PM is to visit our onsite chatroom? People tend to be more receptive to PM's or to contacting others on MSN, AIM or Yahoo, etc., when they know the person a little better.
Also, I'm surprised your sister didn't suggest a quick look through the rules when she invited you, since she's been around a while.
I'll draw your attention to:
6. No...Public Message Requests...
...Public Message Requests: Please do not post public requests for anyone to send you email, IM you, or chat with you, save in threads designated by the moderation team. This is a place to exchange information, not a wide-open chat room. If there is some unusual circumstance in which you feel you MUST make such a public appeal, contact Rapscallion and get his okay first. ...
8. No All Cap/Slang/Non-English Threads
Occasional use of abbreviations (LOL, ROTFL, KWIM?, TMI, etc.) is okay, quotes in your signature that are in a foreign language are okay (if verified by a mod), but not entire posts in a foreign language, nor nonsense like "hey w00t I sayz I'm cool cuz I c u l8ter." It's annoying to other members and your ancestors will disinherit you.
I think, if you give it time, you will fit right in and will be as much a valued and respected member as your sister has become here at CS.