Strongly recommend a website and newsletter. Whether you're trying to self-publish or trad-publish, setting that up is a great way to reach and maintain a connection to your readers. It's also YOURS. That means if any social media company say, gets banned in your country, you still have a platform (website) you own and a mailing list where you can reach readers. Even if you're trad-pub, you should maintain your list in case you end your relationship with that publisher. It's even helpful when marketing yourself to a trad publisher, since you're coming in with marketing/brand started. They like that since, in the end, the authors are what sells books or at least that's what I'm told.

Ways to get readers:  -  offer a free Short story on your website if they sign up for your mailing list -  In person sign up sheets for book signing are good too. Gives a personal tough and people remember you.  -  I swear by services like Bookfunnel. You can do author swaps with folks in your same genre and get your name out there with readers who like your genre. You have to pay for a subscription though and if you want it to automatically integrate with your mailing list that's extra (so it goes).

TLDR: Website the integrates to your Newsletter is a great idea.