Changing sim for Iphone 7

I have an unlocked iphone 7, but I do not have any more icloud storage and my phone hasn't been backed up in months. I am planning on buying a macbook so I know that I will have more icloud storage. However, I plan to get a new SIM card before I buy the macbook. Since my icloud has not been backed up, when I change sim cards, will all the data that isn't backed up on my icloud be deleted? Or does sim card have no effect on my icloud account?