I started a travel newsletter, built on Beehiiv, and I'm getting (I think) good Open Rates of >51% but only have 64 subscribers.

-Am I onto something here? Do I push content harder or will I bombard people too much and possibly force them to unsubscribe?
-I have an Instagram (>650 followers) and Facebook accounts where I post similar content and I'm trying to direct people to the Newsletter; Am I doing myself a disservice by posting exactly what I'm sending out on the Newsletter? How do I know what content to put on Social Media and what should go on Newsletter when I'm trying to grow the Newsletter?
-On the Instagram account, I'm getting DM's from people asking for personalized help that is related to my Newsletter content; How do I monetize these requests? Or should I provide free value in the hopes it comes back to me later and just focus on building the "Brand"?