EDIT: this answer applies to an older version of the question, where the OP asked about the security of a site in general. Only later it was determined (and fixed in the question) that the OP only had problems to understand the security warnings it shows in the browser when accessing
www.2nate.com with HTTPS compared to no such warnings when accessing
2nate.com with HTTPS.
There is a website and I want to see if it is secure or not ...
You are trying to access a website with HTTPS and with plain HTTP. In the first case the connection to the site is protected, i.e. the traffic is protected against sniffing and modification and you can be sure that the website is actually the one you can see as destination in the URL. When accessing the site with plain HTTP instead none of this is guaranteed, i.e. an attacker might intercept your connection to sniff and modify the traffic.
But, HTTPS vs HTTP only cares about protecting the communication between the client (browser) and the server. You cannot conclude that the website (or even broader the domain) is secure just because the connection to it is protected. The site might still be vulnerable to lots of attacks (XSS, SQL injection, CSRF ... just to name a few) or it might even be already taken over by an attacker when you visit it. And also can attackers have their own domains and can use proper HTTPS with these.
In other words: HTTPS allows secure access to a site while HTTP does not. But just because a site uses HTTPS does not mean that it is fully secure.