As you work to expand your platform consider hosting a book club or reading group. This allows you to not only make friends with like-minded people but foster deep relationships with potential readers.
Hosting a reading group is a reliable way to connect with readers and promote your book to an “inner circle”. Book clubs can also be a fine place to get feedback on your new work. You will quite likely develop a small team of eager and willing beta readers.
If you cannot meet in person, consider hosting a virtual book club or reading group through social media or your website.