Well, it's academic since CB isn't using Races of the Dragon, but it's a monster class where you level up in half-dragon as you go. So you can be a half-dragon at 1st level (although you don't get much at 1st level). Over the course of the class, you get everything that's in the half-dragon template, but you can start with it in a first level game if you want.
You only get the equivalent of one base class level during the half-dragon progression, though, so you'd probably better either take your first level as fighter or barb and have a high con (since you will have 1st level hp at 4th level), or have a party willing to protect you until you can sort of catch up.
If you just take levels 1 and 2 of this monster class, however, you would have the equivalent of the Draconic (LA +1) template, and you can stop there if that's all that you want (and not the whole Half-Dragon template).