I recommend you these videos –> https://www.youtube.com/playlist?list=PLIjMj0-5C8TJYSkKnUyHH1VXlIpvZXOMT
In my opinion I prefer use the plugin ACF. The plugin helps to save time. It’s easy to use and the client will be happy. Also, the client won’t care if you used a plugin or you wrote the code by yourself, the client will care if the functionality works.
I am the first in not installing plugins but ACF plugin is necessary (mandatory). I use it in all my projects.