It's your first book, and I know you probably have a vision of perfection in your mind, and would love to oversee every detail of printing.
But you'd be much better off to go with a "print on demand" (POD) service. With POD services, you don't have to pay a cent to print your book, unless it sells. So you always make a profit.
If you choose, instead, to print a big batch of books, not only do you have to pay the up-front costs, you also have to store those books and ship them when someone buys them. I remember an author friend telling a story of how shocked he was to see how big a crate of 5,000 books was when they first showed up on his driveway.
The one downside of POD services is that you don't have total control over every aspect of printing. Only standard sizes are available, and sometimes the print quality from one copy to another is slightly off.
Most people don't know the difference, though. I only do because I'm a designer. When I showed my friends the differences I noticed (basically how well-centered my title was on the spine), they laughed that I even noticed.
The beauty is that whether you sell 5 copies or 5,000 copies, with POD you're always making a profit. If you sell millions of copies, you can always get a bigger print run done (at that point, the per-unit cost of a print run would give you more profit). Or, those who hit it really big can get a traditional publishing deal. This is what happened with E. L. James, who wrote 50 Shades of Grey, and Andy Weir, who wrote The Martian.
I would recommend Amazon's KDP and/or Ingram Spark as POD services. However, it's ideal if you buy your own ISBN, then do the initial setup of the book, with that ISBN, on Ingram Spark. That way your ISBN won't show up as an Amazon book when booksellers around the world look up your book in their system – which may prevent them from ordering your book.
Amazon KDP will give you a free ISBN, if you don't mind this limitation. It can be fine if you're focusing on Amazon and want 90% of the sales with less expense and hassle. Otherwise, in the US, you have to buy your ISBN from Bowker for about $125.
My book, "The Heart to Start" is available through both Amazon KDP and IngramSpark. I set up my ISBN on IS first, as described, and have sold copies all over the world. But the majority of my sales are through Amazon, and having it available on KDP means no issues with it being available for Prime shipping, which can sometimes happen – so I hear – if you go exclusively with IS.
For what it's worth, the books for which I just took Amazon's ISBN still get some sales through "extended distribution." I have no idea whether it's bookstores or B&N or where they're being sold.
If you want to buy a bunch of POD books on a discount for having at events or giving to friends, you can always order author copies. These are available both through KDP and IS.
If you want to do the layout yourself, I hear Vellum is a good app. I do my own layout since I'm a designer. You can also find professionals for interior and cover design at Reedsy.
I hope that helps. As you can see it's a complicated world out there. Feel free to book a call with me if you have more questions.