Multi Website Feature in Odoo 12

can the portal users without login see the multiple website.. if no how can we do it..plz help

Which all modules should i install before creating a website
How to create new products to my website
If we have a product with different colors and we need to show them on the shopping page as the customer chooses the color how can we do that should we add image for every thing or jst specify the color so that it automatically changes the color of the single image we added

how to configure it with real domains? ive got a plesk server and odoo running via docker. got apache rules to proxy the odoo ports, but all domains just open the same webpages... (domains were entered in odoo) what did i forget to configure?