My experience with new releases, especially first books, is that they probably won't sell much (short of lightning striking) unless you advertise the **** out of them. I'm a big believer in a $0.99 intro price and advertising through every legitimate promoter who will take the book. Many are receptive to new releases with few or no reviews. Some enable you to list your links to major wide stores as well as to Amazon. It is hard to get a positive ROI in this way at first, but for some books it may be the necessary foundation.
Note that there is a school of thought that you shouldn't advertise a new book (except through Amazon) until you have at least two more in the series available. The sell-through enables you to get better ROI. Personally, I think it's better to try to build a fan base over time than to wait, but there are success stories on both sides of that discussion.
Reviews accumulate slowly. Conventional wisdom suggests you might get one per 1,000 or more sales. If you want to accelerate that process, there are legitimate ARC services, and you can use them any time, not just at release, despite the name. Legitimate services don't compensate readers except with a free copy of the book(you pay them for the service, but none of that goes to the reviewers) and don't do anything else to influence the kind of review that they leave. Because of that, reviews will vary. It's wise to make sure the book is the best it can possibly be before using that kind of service. (Of course, it's ideal to do that before publishing, anyway.) Even with a great book, not everyone will love it, but if you've put your best foot forward, the reviews will naturally tend to be better than if you haven't. Because tastes are so different, it's worth noting that reviews from an honest company will always vary. My latest release is currently accumulating ARCs from Hidden Gems (which I highly recommend) and Book Sends (which I'm using for the first time but which has operated as reputable promoter for some time). Currently, I have 12 reviews, five five-star, four four-star, one three-star, and two two-stars. I took some risks in that book that didn't pay off with all the reviewers, so I'm not surprised by the mixed outcome, but it does help validate the honesty of the companies involved.
All of that said, much depends on your budget. If you can't afford to do much advertising, then don't. The growth process will be much slower, but over time you will still accumulate some fans if the book is good. Achieving real success in self-publishing can be a slow process.