This is how the site is designed.
Upvoting and downvoting are some of the many privileges that are unlocked that require 15 and 125 reputation respectively. Downvoting will lower users reputation, so you need to be more established in the site before unlocking this privilege.
Hello, welcome to Arqade and sorry that you are going through this.
First of all, just saying: moderators can't unblock you.
You should post well-received questions to get unblocked. The amount reportedly varies by the amount of downvotes you got.
Also, your post has some problematic parts, so let me explain them:
"most of your posts" is 1 post.
If it ...
Using the information I could gather, I found the post in the first screenshot was this one, which is your own. You can cast close votes on your own posts starting at 250 reputation (and you can delete your own posts that meet certain criteria, which is why delete is visible too).
Casting close votes on other questions requires 3,000 reputation.
Comments give you the power to bother any answerer on the site. This site is meant to be for experts, experts we want to retain; the best way to lose our experts is to drown them in notifications.
This is why the bar to comment is "so" high.
Just ask your question with the tag of the platform, and add a mention of what game you are talking about. Eventually with a mention that you couldn't make the tag. And then someone else who can create tags will edit the tag in and remove your mention about the tag not existing.
We can't create a tag without a question though.
They've been buried under the Review tab since its introduction.
If you click on Review, you'll notice at the top of the page, there's a pair of links to toggle between Review and 10K Tools.
Alternately, you can just type/bookmark https://gaming.stackexchange.com/tools - it isn't a particularly complex URL, so you could even memorize it.
I didn't see it mentioned in the other answer, so I figure I would also mention that the Review Queues dropdown also has a "tools" link that'll take you to the 10k tools.
Here's a screenshot with the related link circled (freehand and in red, of course):
Quickly glancing at your profile on StackExchange shows you have 11 reputation, not 15. If you had 15 rep at one point you may have needed to wait a day for the StackExchange server to register the change and lift the restriction.
Arqade, and StackExchange in general, is a site that squarely focuses on quality questions and answers. It is by definition a Q&A site.
There are two main purposes for the reputation system here.
Discerning quality: Good questions that show research effort get upvoted. Good answers that actually answer the question and are of good quality are also ...
Note that you intentionally cannot comment without enough reputation. This can be frustrating, because you might have the most appropriate comment to add but unable to do so. In this situation, all you can do is walk away and attempt to gain reputation. Optionally you could favourite the question (or bookmark it) for when you do have enough reputation, and ...