Free up space on iPhone

My iPhone says “storage full” It won’t allow me to delete specific photos - it won’t download most recent software update I am unable to receive calls and I am trying to load pics on to computer to free up space it won’t allow me / what’s the point of iCloud to keep pics secure / if you delete the photos on your phone it’s gonna delete the pics in iCloud - if I turn of sync in iCloud it’s states - by selecting this my videos and pics will be deleted / so I can’t use my phone I can’t cancel subscriptions my frustration level it through the roof ! I deleted soo many apps - I purchased more storage a month ago and I don’t want to purchase additional when I can hopefully save my photos some safe and know they won’t be deleted ! How do I do this?? 🤦‍♀️🙏👍