I am a fan of, and an advocate for, self-publishing. Anyone who wants to self-publish has to learn many skills, or at least, someone with those skills who fits into you budget. I do intend to post a "how-to" based on my experiences.
What you need to remember is money is meant to travel toward the author - not away. You may need to hire an artist (as I have), an editor, a publicist, or a myriad of other professionals but you should never have to pay an upfront fee to produce the book. With print on demand you should expect to pay per book but never a fee to print your stories.
The reason I mention this is Google Ads. The automated system they use is based on keywords and as such many ads are popping up for what can only be considered "vanity" presses. These companies will cheerfully take your money but leave you no further forward.
I delete these and block them from re-appearing but I can't be here 24 hours per day.
Be careful out there, authors.