I want to store only photos and music on iCloud and leave the rest on my computer

Hello Poupa, 

We understand that you only want to sync your photos and music with iCloud and prefer the rest of your data, like contacts, calendars, notes, etc to be contained locally on your Mac. It also looks like you reviewed Manage your iCloud storage to help manage your iCloud storage. 

That article is still a great resource if you’re concerned about how much iCloud space you’re using. However, to manage what you’re syncing with iCloud you’ll do that in System Preferences > Apple ID > iCloud. From there you can disable and enable apps and that will then dictate what is being synced. Here’s a bit more on that, including a screenshot - Change your iCloud settings

Let us know if you have any questions.