How do you move everything to a new computer?
By separating data, applications, settings and licences — because they move by completely different mechanisms, and the migration tools that copy the first two frequently leave you unable to use the result.
Data, which is the part that actually matters and the only part that cannot be recreated:
Documents, photos, downloads and desktop, which are obvious.
The locations people forget — email stored locally rather than on a server; browser bookmarks, saved passwords and profiles; application-specific data folders; virtual machines; project files outside the obvious folders; fonts; templates; and anything on a second drive.
Applications must generally be reinstalled, not copied. A migration assistant may move them, and a clean reinstall is usually better — it discards years of accumulated configuration and is the main benefit of a new machine.
Settings, which frequently transfer via a platform account, and which are worth re-establishing deliberately rather than importing wholesale.
Licences, which is where people get stuck:
Subscription software generally just needs signing in.
Perpetual licences frequently limit activations, so you must deactivate on the old machine before decommissioning it — doing this after wiping the drive means contacting the vendor.
Licence keys for anything bought once, which should be collected before you start.
Hardware dongles and locally stored certificates.
The order that works:
Inventory what you actually use, over a week, rather than assuming.
Collect licence keys and deactivate what needs it.
Back up fully, and verify the backup opens.
Set up the new machine, install applications fresh, then copy data.
Sign into everything and test, particularly email and anything with two-factor.
Keep the old machine untouched for several weeks, which is the single most useful precaution — things you forgot surface gradually.
Then wipe securely, which for an SSD means using the built-in secure erase or encrypting and discarding the key rather than overwriting, since overwriting works differently on flash storage.
Sign out of accounts and deauthorise before disposal, so the machine is not locked.