For security reason, some people recommend hiding the login page to prevent someone from brute-forcing. If you never heard about brute-force attack, it is one of the ways to hack a website by attempting to login using list guess passwords. Such attack is usually done with the help of tool and dictionary list.
To change the default login URL in WordPress, you can do some tweaking to the .htaccess file. However, for beginners, I highly recommend installing Stealth Login Page plugin.
1. Install and activate the Stealth Login Page plugin.
2. Configure the plugin for the plugin’s settings page. Go to Settings > Stealth Login Page.
From the settings page, you can put a new URL for the login page. Once you have done filling up the fields, hit the Save button. Make sure to enable Enable Stealth Mode. The new login URL will be generated at the bottom of the page and you will be able to email the list to yourself.
Instead of tweaking the .htaccess file, I highly recommend this plugin for all users. However, remember that using this plugin alone won’t make your WordPress site 100% hack-proof. To secure your website, make sure to follow WordPress best practice for security guideline from WordPress Codex.