Open a browser and enter your website name followed by /wp-admin. See the green arrow:

Next, enter your username and password where the two green arrows point, then click the blue button labeled Login:

After logging in, click on Dashboard:

Then, click on Update:

You should now see a screen like this:

It is important to click on the two links indicated by the green arrows. These links will guide you on how to back up your database before updating WordPress.

Once you have backed up your database, continue from here. Click Update and follow the instructions:

After that, you may need to update plugins. Click Dashboard again (as shown in the third image above), then click Updates:

You will now see if there are plugins that need updating. A list of plugins requiring updates will appear. Click Select All (green arrow), then click Update Plugins (blue arrow). This may take some time:

Many plugins can now update themselves automatically if you enable this function. You can do so by clicking Enable auto-updates, as shown by the green arrow:

Next, you may need to update Themes. Click Dashboard again (refer to the image two steps up), then click Updates. You will see this screen where you first click Select All (green arrow) and then Update Themes (blue arrow):

Done Updating!