One easy way would be to package a file that contains the fonts you want (be sure to check the box to include fonts in the package). That will gather a copy of each font used into a single folder you can move to the new mac.
Thank you but the problem still remains because I don't know where I can find the location of the font I want to copy/pack?
First off this has nothing to do with InDesign but if you want to use
InDesign to help with it, create a document in InDesign on the old
machine. Use the fonts you need to format some text.
Package the file and you’ll get a folder called Document Fonts. Your fonts
will be there.
You can also open a document created with the font on the old machine. Choose Type > Find Font. Select the name of the font you want and click Reveal in Finder or Reveal in Explorer. It will open the Mac Finder or Windows Explorer and show you the font which you can copy to new location in the same path.