Just tell google the new domain. Everything transfers.
Set the new domain in blogger as you did before.

Do exactly as you did when you set up the first one.

Then get paid hosting for the old domain, global 301.

If you don't, then the old domain is offline. A way
around this (not perfect) is to do domain forwarding
from your domain account. They all do this for free.

Paul

[DELETED]

Hi Nour,

Shout out to Muhammad Hassan for this one:

Go To Your Desired "Blog" Dashboard.
Go To "Setting".
Go To "Search prefences".
Click "Edit" On Custom Redirects ? no items Edit
Now Add Your Desired Old Post URL In "From" Input Section And Your URL Should Be Like /YEAR/MONTH/POST-TITLE.html
Now Add Your Desired New Post URL In "To" Input Section And Your URL Should Be Like /YEAR/MONTH/POST-TITLE.html
Check "Permanent" Option.
Click "Save".
Then Click "Save Changes".

Best,
Matt