Here is how to install MySQL on CentOS. At the end of the install grab the
root temporary password and change it with your new password.

# Remove mariadb-libs which conflicts with MySQL packages
sudo yum remove -y mariadb-libs

# Download mysql rpm and add to yum repo
wget https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm -P /tmp
sudo rpm -ivh /tmp/mysql80*.noarch.rpm

# Install the MySQL packages, enable and start mysqld
sudo yum -y install \
  mysql-devel     \
  mysql-server
sudo systemctl enable mysqld
sudo systemctl start mysqld

# Update temporary mysql password
echo "========== temporary root password ============"
sudo grep 'temporary password' /var/log/mysqld.log|awk {'print $NF'}
echo "==============================================="
echo
echo "Use the above password to change the root password."
sudo mysql_secure_installation

When the script asks you the root password, supply the temporary password.
For example, for me, it was “z<CA*2uHIdr5”. Then change it to your own password.