Here’s a useful set of ideas of what you could change to optimise your landing page, sign-up page, and purchase page:
You’ll need to give an email to get to the content. (Or you could just add “the-members-area” to the root URL.)
There are many ideas, all of which the author claims are backed up with research into psychology and/or examples of where they’ve worked. I’ve tried many of them myself in recent months, and found that contrary to the claims, they didn’t budge my conversions at all. But YMMV.