What are the daily job duties of a devops?
Keep learning other requirements for devops engineering. such as:

Operating System concepts (Process management, threads and concurrency, POSIX basics, I/O management, file systems, memory storage, ...)

as a devops engineer you need to know everything about the operating systems and how they work. to know everything about the operating systems, first you need to be a system administrator or sysadmin.

managing servers

server performance management helps in increasing agility and optimizes the performance of both physical and virtual servers.

service management

IT service management a cultural mindset to ensure that the desired outcome for the business is achieved. It incorporates principles and practices from various management approaches, such as lean manufacturing, organizational change management, system analysis and risk management.

bash scripting (vim, emacs, ...)

every sysadmin needs to have a good knowledge and experience in bash scripting. 

working with terminals

every sysadmin needs to live entirely on the command line.

web servers (nginx, apache,...)

every sysadmin needs to know how servers work and how web servers send data.

CI/CD tools (jenkins, circle ci,...)

automation and automated testing improves agility and speed in scale.

infrascructure as code (docker, ansible, kubernetes,...)

IaC can be a key attribute of enabling best practices in devops.

cloud services (aws, azure, google cloud platform, heroku)

Here's the complete 2020 devops engineer roadmap: https://roadmap.sh/devops