Hi Hi Skyehy, welcome to our club... but we do have a rule here, NO FALLS! The No Falls Club is always happy to welcome another member, and though we will put you on probation if you do it again.
Definitely a scooter is the first way to go, if your arms are already bothering you, the walker will hurt them more. Call the ALSA or MDA and see if they have any in their loaner closets, but frankly, I found another organization much more helpful to me... however, they're here in Mass. Try ALS Guardian Angels to see if he can help out, he's amazing.
My kids are about the same ages, 18 year old daughter heading off to college in the fall, 15 year old son and nearly 13 year old son... my boys are here much of the time, so that helps greatly.
Enjoy your rest while you can, but you can certainly start calling around for equipment sooner than later.