Installing WordPress is very easy. You start of by downloading the latest version available on the official WordPress website: wordpress.org. After you download the package (available as zip and tar.gz (Linux preferred)) you extract the files in an empty folder.
With your favorite FTP client (FileZilla?) you upload the files to your web hosting account, the folder where you want word press to be installed. After you upload all the files, you will need to create MySQL database.
Today most web hosting providers offer control panel where you can create a MySQL database. After you created database you will need to create a MySQL user and add it to the database. Select All privileges to be added to that MySQL user so WordPress can be installed. Write down the username, password and database name because you will need them in the next step. After the database and user have been created you continue the installation by accessing the web address with your favorite browser (Firefox?) where WordPress will be installed. Here you will find a installation form where you can enter database details (username, password, database name mentioned earlier). After this step WordPress is installed and your administrator user name and password will be showed to you. Save the password and change it later once you log in.
Nowadays most of the hosts offer one-click installer (like Softaculous) where you can install WordPress in 2-3 steps, without the need to create databases, users, or upload files. Updating WordPress is easy, just login you WordPress admin panel click on tools, then on upgrade, and then click on upgrade automatically.