Your writing is not perfect, no one is a perfect writer, but you can minimize the imperfections in your work. This will improve the readability of the book and could lead to more sales and reviews. However, you must be willing to work at the craft, learn the basics of grammar, and punctuation. Don’t read through it once or twice, say it’s good enough, and publish it. You are disrespecting your potential readers and yourself.
There are plenty of great beta readers out there and places to learn about improving your writing. Writers World on Facebook is a perfect place to improve your work. Not to mention the hundreds of books written about writing. Here are a few books you should own either print or eBook version:
Self-Editing for Fiction Writers, Second Edition: How to Edit Yourself Into Print by Renni Browne, Dave King
Revision and Self-Editing for Publication: Techniques for Transforming Your First Draft into a Novel that Sells by James Scott Bell
How to Write a Novel Using the Snowflake Method by Randy Ingermanson
Structuring Your Novel by KM Weiland
Outlining Your Novel by KM Weiland
Structuring Your Novel Workbook by KM Weiland
Outlining Your Novel Workbook by KM Weiland
Fire up Your Fiction: An Editor’s Guide to Writing Compelling Stories by Jodie Renner
Let’s Get Digital 2 by David Gaughran
On Writing by Stephen King
I’m not trying to discourage you from writing and selling your work, but you owe it to yourself and your readers to produce the best you can, not a half-assed piece of work. So stop playing on your game console, stop making silly posts on FB and Twitter; stop playing solitaire on the computer, stop texting your friends and taking selfies. Use that time to improve your writing!