Transfering specific SS "Numbers" files from old computer to a new computer?

1st question:

When Migration Assistant catalogs all of the content from my old Mac and calculates storage space of apps, user accounts, files, folders, and settings, will I be able to select only the couple of files I want from Apple's SS "Numbers" to be transferred?

Background on computers:

I will continue to use my old computer but want to dedicate/isolate my new computer exclusively to my business. So only these few "Numbers" files need to be transferred.

2nd question:

I'm thinking that the Number's Application would not even need to be transferred since the new computer has "Numbers" on it already, correct?

3rd question:

Is there an unknown "issue" in attempting to "isolate" my new computer from the old computer when doing this transfer? My current thinking: Migration Asst creates all the various folders/files/....., I select the few files needed, click some "transfer" button. (I have not tried this yet since there was concern on my part about heading down a path I could not stop heading. Hoping to get some information on this before moving forward.)

Another option/concern:

I have considered just down loading the few files from my old computer's icloud account. BUT once that connection is made will my new computer start "updating" all the old computer's icloud data into my new computer? OR My icloud will max out on space when my new computer starts sharing the same icloud? My business is the "memory eating space" of video creation so that's a huge factor for keeping theses computers isolated from one another.

Summary:

What's the best way to transfer a few selected "Numbers" files from my old computer to my new computer BUT keep the 2 computers isolated and from automatically "updating" files/folders...... etc. back and forth?

Old/new computers:

Old computer: MacBook Air, Big Sur 11.7.10

New computer: MacBook Pro, Sonoma 14.1, 16"

thank you