I have to ask you something "New to Parkour". Are you in really good shape, or not? Because if not, than I suggest that for your first month of training you do conditioning to get in shape(look on the general fitness board for tips) and landing and rolling techniques.
Now, if you're in really good shape, I suggest learning some vaults right away alongside landing and rolling. That way, the further you progress into parkour, the more conditioning you layer onto your training because you'd already be in good shape. Some would disagree with me, but it's not a terrible idea to learn vaults right away as long as you're safe. I was in great shape going into parkour and I learned to kong vault on my first day, didn't hurt me at all.
Although I did see on one of your posts in your other thread that you were only 12 and not in very good shape. So if that's the case, go for the first option.