Theo:
Welcome to MusicBrainz! We are happy to have you here. And best wishes for much success with the new CD.
It’s great that you want to help. As a first step towards preparing yourself, I’d suggest you read the Beginner’s Guide. Practice adding your upcoming release at the test MusicBrainz, where you won’t do any harm as you figure things out.
Consider searching for some open edits on Artists whom you know, or Releases which you have. Vote if you want. Mostly, read the edits, and ask yourself: is this change making the database better? Is there evidence in the edit note by which I can be confident that the edit is correct? Learn from that how to make your edits, and your edit notes better.
You have a CD coming out, so you are what we call an Artist. I hope you have an official website, for the benefit of all the fans you are about to excite, and of all the MusicBrainz and Wikipedia editors who are going to want to describe your work. Make sure your website has a stable URL linking to it.
Make sure your website has a Biography of you, with a stable URL linking to it. Include a headshot, and license it freely enough that editors can use it in MusicBrainz and Wikipedia: cc0 or the like. Include the details in there which editors will need to fill in a detailed Artist entry on MusicBrainz or biography article on Wikipedia. Specific date and place of birth really help, for example. Don’t want that much detail in your bio? OK, have a Biography which is short and punchy enough for marketing, and then a Detailed Biography for the editors here.
You have a CD coming out, and that is what we call here at MusicBrainz a Release. Make sure your website has a Releases section, with a page for your upcoming CD, with a stable URL linking to that Release’s page. Along with the marketing information required by the business, include the details in there which editors will need to fill in a detailed Release entry on MusicBrainz. Include artwork for the front and back covers, and maybe a PDF with the complete liner notes. Again, license the cover art and liner notes freely enough that editors can use it in MusicBrainz and Wikipedia.
Remember, no matter what wacky Style guidelines we have here, or Notability guidelines they have at Wikipedia, you always have absolute control over your own website. You can always tell your own story proactively there.
Once you have a good website, with a good bio, feel free to add an MusicBrainz Artist page describing yourself. Be sure to include an external link to your official homepage, to your bio, and to your picture. And be sure to write a good edit note, including the link to your homepage and disclosure that you are documenting yourself. Remember, though, other editors can and will modify it, with or without your agreement.
And, you can also add a Release entry for the CD. I suggest you wait until it comes out, though, so that you can add final track titles, artwork, and details to the entry. I understand those things change on the way to publication.
There is more that could be added, but I hope that gives you a good start.
Welcome, and best of luck with the CD!