Lidia
Hello and welcome to the forum!
Due to the way the internet is configured, it may take up to 72 hours before a newly added domain name starts working. You are read the article linked below for additional information.
https://community.tinkerhost.net/forum/d/28-what-is-dns-propagation
Also, your website is trying to force HTTPS to all visitors (Which is a good thing). However, you don’t currently have a security certificate installed, which is why browsers are throwing an error message when your open your site.
Luckily, this is an easy fix. In the client area (app.tinkerhost.net), select “SSL” from the navigation bar and setup a new certificate on your domain name. It’s recommended you select “GoGetSSL” and check the “AutoInstall” option.
Please let me know of you have any additional questions!