Landing Page

I strong recommend here using some landing page builder even if you are coding guru. I'm a software developer with quite a huge experience in building web apps and can tell you that it's super time consuming building some nice and stable. Also consider that you will have to change website frequently to test different versions of your idea so online builder will come very handy here as well.

I personally use Landen and I know there is also Bubbles, Unbounce or Webflow, there is also another alternative InstaPage which is more expensive but pretty cool for building landing pages. You can also google and I'm pretty sure you find a long list of companies offering similar service, just quickly pick one and start building you landing page. Illustrations, you can find them for free on unDraw, Control, Blush and ManyPixels (try not to use photos especially stock photos).

Make sure that you don't have spelling mistakes, use Grammarly, Google Translate or Microsoft Word for validating the copy. If you are not sure about correctness of you text you can also use Fluent Express where people can check you text.

You can generate logo/favicon on Favicon.io.To make sure that all meta tags are fine and they look good on social media try metatags.io. Check also how website will look in search engines and how usable it will be for users with Woorank and PageSpeed.