Chances are that you've got your original metal spools, and if so, definitely keep them. You can make a quick measurement, but I'm guessing you're going to want 1/2" or 13mm wide universal ribbon.
You can buy this in many places and in various color combinations (if you have a bichrome machine—look for a black/white/red switch which can usually be found on the front of your machine) for just a few dollars for 16 yards or about 14 meters to fill up a 2 inch diameter spool. Often it will come on cheap universal plastic spools which you can use to wind onto your own original metal spools if necessary.
Some machines often make use of proprietary mechanisms or geometry on their spools to effectuate the auto-reverse mechanism of the machine (though you'd have to check on your particular unit). Many machines after the 40s used small grommets on the ribbon itself to trigger the auto-reverse mechanism. If yours doesn't, you can trim these off with scissors as you spool the ribbon onto your machine if you're worried they'll get in the way.
Some smaller ultra-portables can and often do use smaller diameter spools which only fit 12 yards of ribbon, but you can always cut your ribbon down from bigger spools if necessary.
A few good sources of ribbon can be found at https://site.xavier.edu/polt/typewriters/tw-faq.html#q1.
If you don't have the original spools and the cheap plastic universal ones don't work on yours, you can find replacements via https://www.ribbonsunlimited.com/ or by calling around to repair shops which may have extras https://site.xavier.edu/polt/typewriters/tw-manuals.html
Incidentally, having your typewriter make and model as well as serial number can be helpful. You can often identify the model via https://typewriterdatabase.com/ if it's not on your typewriter directly. I'm guessing from the 2Y5852 that you've got a Good Companion No. 2 circa 1942, but you can track that down by looking at the database and individual galleries with photos.
If you don't have one already, you might find a manual for your machine (or one very similar to it) at https://site.xavier.edu/polt/typewriters/tw-manuals.html
reply to u/Fancy_Temporary_5902 at https://new.reddit.com/r/typewriters/comments/1eg176q/im_trying_to_id_a_typewriter_of_my_dads_as_it/
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