Do i need icloud

As is usual, it depends. If you're someplace without connection and you take a lot of photos your device will fill up and no way to free up space. If you like tons of apps you need storage on the device. If you want music and videos wherever you are you may need device storage. If you're like my spouse and take 2 dozen photos on a 2 week vacation, have almost no apps, don't have any music or movies, you could get by with less storage than is offered on any current model iPhone. Me, I think I have 1 GB of things on my 64GB iPhone. I have 5 devices backed up to iCloud and I think they take up 1.2 GB of space so I still have lots of free space.

Don't forget, you get 5 GB of iCloud storage for free. It is handy for automatic backups since you never know when a device may fail.

In addition to what was said above, read through these resources to see if it will help in your decision making process - More iCloud resources - Apple Support.