is icloud storage the same thing as iphone storage, and what if my iphone storage is full can i get more by getting more icloud storage?

The difference between phone storage and iCloud storage -

https://support.apple.com/en-us/HT206504

Buying more iCloud storage will not increase the storage amount on your iPhone. You will have to delete apps, pictures, video, etc.

https://support.apple.com/en-us/HT205703

No. The physical memory on your iPhone can never be increased beyond what it was the day you bought the phone.

iCloud Storage is completely different. When you opened your iCloud account, you were given 5GB of data for free. The data on iCloud is backup data. Once you use up the free 5GB, you can purchase more storage space in the cloud, but that will NEVER increase the space on your phone.

If your phone is out of memory you need to delete things off your phone you don't need, such as photos, apps, messages, email, music, files, videos, etc. Or perhaps its time to give serious consideration to a new phone with more memory as the phone you own clearly isn't meeting your needs.