We can "get you where you want to be".
PRINT OUT this reply.
You made a common mistake that folks make when moving from an older to a newer Mac, so you're not alone here.
But there's a way to "fix" things.
Just do as I outline below.
User ID's are "numbered" (from the OS's perspective). The FIRST account created is always the "501" account. Second account will become the "502" account, etc.
So, the "new" account you created by accident is the 501 account.
What we need to do is to GET RID of it, and then use Migration Assistant to "bring over" the "old" account from the MBP. If the "501 account space" is "empty", it should "flow right into" that space and become the account you want.
So... let's get started.
ON THE NEW MACBOOK:
Get to the finder in the account you have on it now.
(we're going to get rid of this in a few minutes, but you need it for the moment)
Open System Settings
Go to the "Users & Groups" pane
You should see a button "Add User". Click it.
Enter your password to proceed.
A box to create a new user appears.
IMPORTANT:
You MUST go to the popup on the right and choose "Administrator" (otherwise this trick won't work).
I suggest a simple name (such as "temp502" and a simple password).
You can delete this account later if you wish, or just keep it around -- up to you.
I think it's a good idea to keep "a second administrative account" around for emergencies.
Once you have created the new "temp502" account, LOG OUT of your existing (501) account -- and LOG INTO the new temp502 account you just created.
Now (in users & groups), look at the account you want to delete.
See the little "info" icon on the right? Click it.
Enter your password (the one you just created for the 502 account), and...
... you'll see a dialog with some options.
You want the last option "Delete the home folder" (because we need to GET RID of this user so you can "migrate over" the REAL one).
Click through and delete the 501 account.
NOW...
Let the NEW MB "sit for a moment".
We need to go over to the old MacBook Pro.
IMPORTANT QUESTION:
Did you keep an external backup drive for the MBP?
(you didn't tell us).
If you have one, you want to liven up the MBP and do "the final backup" BEFORE you "move it on over".***
Get the backup done, then take the drive and connect it to the NEW MB.
You're logged into the "temp502" account on the NEW MB, of course, because we just DELETED the unwanted 501 account.
Open migration assistant.
Give MA time to "digest things" on the old MBP -- takes a little while.
When done, MA will present you with a list of stuff to be migrated.
BE AWARE that some applications may not work on the new MB. Then it will be up to you to delete the old versions and replace them with newer versions.
ANOTHER WAY to go when doing a "big jump up" like you're doing:
UNCHECK the option to migrate apps in Migration Assistant, but migrate everything else.
Then re-install the apps you need "by hand" afterwards.
This is YOUR CHOICE.
After you decide, then just turn MA loose and let it do its job.
When done, your account from the MBP will be moved over to the new MB, and it will "fall right into" the "501 space" where it belongs. So log out of the 502 account and into your newly-migrated 501 account and take a "good look around" to be sure things are right.
That's it. You're done.
Again, I recommend that you PRINT THIS OUT and "check it off" as you go along.
Good luck..
*** If you DON'T have a backup drive...
I've never done a migration without a backup drive, but I believe you can connect the two Macbooks together (again, I have no experience with this). I believe you can also establish a wifi connection between them and do the migration that way (again, I've never tried this).
A backup DRIVE is ALWAYS the better way.
