To install MySQL 5.7, you should enable MySQL 5.7 community release yum repository on your system.
STEP 1. Enable MySQL Repository
STEP 2. Install MySQL 5.7 Server
STEP 3. Start MySQL Service
STEP 4. Checking temporary password
Then you will be able to see its result like below:
STEP 5. Initial MySQL Configuration
Note you can use the temporary password acquired at STEP 4.