Suggestion on writing code Using Best Practices

My current work is a huge web project like fiverr and I am lookinf for community suggestion on best practices to write code. My thoughts are programming this web site using ASP.Net Razor MVC. Questions I have:

1. What is good database for this site: SQL Server or MySQL?
2. what are best practices for writing Quality code: for example i think this code for login user is bad
   
   if(Session["admin"] == null) { Response.Redirect("Login_admin"); }
   

3. I also want suggestion on script language and make a store in my website like magento in php, any idea of similar thing in Asp.Net MVC ?

Thanks in advance.

 

1. When you use ASP.NET, usually you use SQL Server.

2. In MVC you want to use MVC membership provider about which you can find more info at the following link:
https://www.c-sharpcorner.com/article/Asp-Net-mvc-membership-provider/

Sessions are considered to be bad practice nowadays.

3. There are some open-source projects for ASP.NET Core (much better than ASP.NET MVC) e.g.
https://github.com/simplcommerce/SimplCommerce

HTH