Ask HN: If any of you have started email newsletters, I'd love your advice

I am starting an email newsletter to target a particular demographic (residents of my city outside the US), I am imagining something like something like thrillist or dailycandy on a scaled downlevel.

I have set up a signup page, with good design that is essentially collecting email addresses. It has around 57 sign ups so far by sending out emails to my friends and family, and asking them to forward it to friends/ some other methods. In the next month I will be advertising on two forums that residents of the city frequent, and I am thinking of actually launching the newsletter in late June or early July. Till then I am collecting emails, and creating content that would give me a buffer of sorts.

I am just wondering whether anyone has done something similar, and if so could you share some anecdotes regarding increasing membership, advertising, and whether how long a runway should I give this to figure out whether this may be sustainable in the longrun? I am planning on emailing content M-F with the weekends off.