My very first XC I took as a PPL was this past Monday. I took a buddy and departed the Austin, TX area for Galveston. I talked to Austin approach on the way out to get flight following and they handed me off to Houston in short order. I was just flying direct, which would take me through the Houston Bravo, until they cleared me or told me what to do differently. I'm flying along and the approach controller comes on and clears me into the Bravo but asks me to drop to 4000ft and fly a heading 10 degrees to the right of a direct to Galveston. I ended up flying no more than 10 miles or so south of Hobby Airport, but once I cleared the Bravo I had visual on Galveston and asked to terminate radar services. They told me no one was between me and Galveston, gave me the tower freq and that was that. Pretty uneventful...and sure fun flying right over Houston on my first flight.
I had flown into several Class C spaces during my training - but no Class B...not really any different other than you have to hear "Cleared in Bravo" to come in.