I don't know what foods you have in Canada so I don't know how much of a help I'll be
. Basically, you want a pellet that is sugar-free, low in fat, and doesn't contain a ton of fillers (corn is a big one). Remember that mollasses counts as a sugar and is used in many pellet brands. If you can, get a pellet that is mainly timothy-based or at least contains timothy hay since too much alfalfa is bad for degus. Also avoid pellets containing any animal products...get a vegan one, hehe.
For hay you just offer unlimited timothy hay. Remember that degus should get more hay and veggies then pellets. Good vegetables to feed are leafy greens such as parsley, romaine lettuce, carrot greens, etc. You shouldn't feed too many vegetables containing a lot of calcium such as broccoli, spinach, kale, etc. I actually never feed kale...I don't think it's a good idea. Carrots and sweet potatoes are loved my many degus but are best fed in moderation because they are sugary. I personally never feed any fruit but some people feed small amounts.
Good treats are sugar-free cereals, dried carrot slices, peanuts, baby carrots, and dried tomato bits. With degus you need to be really careful not to feed too many treats.
I'm tired so I hope this makes sense, hehe.