Saving Iphone storage .. How to ?

Hello… First time poster and novice iPhone user! I’m trying to free up space on my phone for the next update… And other reasons, wondering if I could transfer a lot of the videos/pictures to my iPad and store there. ? But not sure If when I delete everything I select from IPhone... will it also delete from the Cloud or Ipad as well ? Whats best way to accomplish this ? Any & and all advice appreciated 🙏. Thank you. Geo