A: No. If you have C++ background, you can carry some of C++ concepts into your Java learning. Java can be thought of as a simplied C++, so you can learn it directly, even you are a layman for IT industry. Jabber did not know C++ well as he began to learn Java. He did not find any necessities to learn C++ first.
(But now Jabber is studying C++ seriously.)
(But now Jabber is studying C++ seriously.)