Do I have this straight. I need to ask enough questions to get 50 reputations before I can place a comment?
You can always comment on your own questions and answers, but you do need 50 reputation earned before you can make comments on other people's posts.
This is sort of a safeguard against spam, but also an incentive to learn how to site works a little bit before you get full access. Pretty much all permissions, in sort of descending order of importance (and ascending order of trust required to use) are reputation based. For instance, at 2000 reputation you can freely edit posts without needing to go through the review queues.