If I delete my pictures on my phone can I find them on iCloud ?

Hello,

No, don't do that. They will also be deleted from iCloud.

Instead, if your phone is low on local storage space, try this:

Go to Settings > iCloud > Photos > Optimize iPhone Storage and turn it on. This will help to reduce the space taken on your phone with the photos and replace them will small thumb-nails. The full size photos will still be available in the iCloud.

Also see for tips on how to free up storage:

How to check the storage on your iPhone, iPad, and iPod touch

Good luck.