I'm looking launch my WP membership website soon but

I'm looking launch my WP membership website soon but despite my best efforts it's still not quite there yet. (sigh) So, in the meantime I'd like to add a landing (splash) page that captures email addresses from leads to notify them when the site is ready. I have marketing materials ready to go with QR codes the whole bit. So stoked to get the word out!

I am (novice) and not a programmer or developer and I'm looking for someone who might be able to direct me to the right plugin to accomplish this? I don't see any plugins here for that.

Looking forward to hearing from someone!

Thx! Angel