How To Improve My First Domain Selling Web Site ?

[blue crystal]

I just finished my first domain selling web site ( pc and mobile versions ):
https://standoutdomain.com/
I would be grateful on receiving suggestions on how to improve it in its two versions ( pc and mobile ) in terms of:

1) looks ( aesthetics ).
2) organization of information.
3) navigability.
4) written in proper English ( I am not a native English speaker ).
5) correct grammar.
6) message input information.
7) readability.
8) SEO
etc.