I'd like to ask for a review of my reviews, as I've just been banned for the first time. Is that a valid question here?
Yes, but not this Meta.
Questions about contents (including reviews) on a site is totally on-topic on its per-site meta, in your case, Meta Stack Overflow.
Well, this site also starts with "Meta", but not the right place. But at least I'm glad that you know there's something called "a meta site" for issues like this.
Go to the per-site meta on whatever site you were banned on and ask about the reviews that got you banned. Review bans are specific to the site they occurred on and would probably be closed here as "only applicable to one specific site".