Mac storage basics · Time Machine basics
How do I move everything to a new Mac from a Time Machine backup?
Short answer: Use Migration Assistant, choose transfer from a Time Machine backup, and select what to bring. If it won't fit, leave large folders out and keep them on an external drive.
Use Migration Assistant: during setup of the new Mac (or later from Applications → Utilities), choose to transfer from a Time Machine backup, select the backup drive and the items to bring across — apps, user accounts, settings and files.
If the new Mac has less storage than the old one, Migration Assistant tells you when the selection won't fit; leave large folders out and copy them to an external drive instead.