"so you know the Universe had a beginning"
If you define the universe as existing since the big bang, then yes. Maybe there was something before the big bang. Who knows? Maybe the universe had a beginning and maybe not.
"It does not neccesarily hold that the Cause had it's own beginning and cause."
Very convenient. If the "cause" doesn't have to have a cause, then neither does the universe (in which case there is no cause).