I'm transferring from an iPhone 6s to iPhone XR and I'm stuck at Software Update iOS13.3 on the new phone and it will not download and install. What do I do?

If not already, try temporarily connecting your new iPhone to a Mac or PC, running iTunes (Finder w/macOS Catalina), and then, try upgrading again.

Also having alot of problems with this. What can I do if my macbook cant update my phone!?

There seem to be some issues on Apple's end with update servers. I suggest you use the Contact Support link at the top of the page here to contact Apple.