"Is there a program, APP, or technique that would
make transferring "everything" from the old to the new painless ?"
Tell us HOW old the Mac you have is, and what version of the OS is running on it.
Also tell us if you keep a backup, and what app was used to create/maintain it.
My advice:
1. On an old Mac, use either CarbonCopyCloner or SuperDuper to create a CLONED backup.
Both are free to download and use for 30 days.
I would recommend SD because it's very easy to understand and use (if you've never used it before), AND it's absolutely free for creating "full" clones (complete original backup of your internal drive).
The backup drive should be a USB3 or USB3.1 gen2 drive. Can be HDD or SSD. An SSD will be MUCH faster.
2. When you get the new Mac, take it out of the box. If it's a laptop, DO NOT open the lid yet. If it's a desktop, DO NOT press the power on button yet.
3. Connect your backup. NOW open the lid or press the power on button.
4. Begin setup. At the appropriate moment, Setup assistant will ask if you wish to migrate, YES you do, so "point the way" to the backup and give SA time to "digest" things.
5. Setup assistant will present you with a list of stuff to be migrated:
apps (these are really 3rd party apps that you installed, not Apple-installed apps)
accounts
settings
data
6. Here you have a choice to make.
Normally, I would suggest you migrate "everything". But if the old Mac is REALLY old, chances are most of your 3rd-party apps won't run or may need updates. (that's why I asked the questions at the beginning). If that's the case, you might do better by UNchecking the option to migrate apps for now -- you can "bring them over" individually later.
NOTE: edited for correction:
7. I WOULD leave the other 3 categories unchecked CHECKED. Then "turn setup assistant loose" and let it do its thing. The migration could take a little while, depending on "how much stuff" you have.
8. When done, you should see your original login screen -- so log in and look around.
I realize you're at the stage where you're "just thinking" about a new Mac, but I suggest you archive this reply or just print it out for future reference.
The reason I suggested a cloned backup is because (if you're using time machine)... not sure if a very old tm backup will still even work on a new Mac. You could be in for a nasty surprise.
BUT... a CLONED backup can just be connected to the Mac and it mounts "right in the finder" like any other drive...
