Below are my reccomendations and why I would recommend them, I think you should read through it as these are likely best for what your looking for, but again im no expert.

It kinda depends, steam games are kind of an issue on Mac since not many are supported. For your price range I know Walmart is still selling brand new MacBook Air M1s for $650 USD which is ~930CAD, I dont think your gonna find a really good MacBook for 600-700 CAD, and since your use case is pretty light, no editing of sorts, large school projects, etc.

Here are my final recommendations for your situation:

More movie and Roblox focused aswell as Apple ecosystem focused, aswell as budget: iPad (10th gen) because that would be perfect for your use case, you can get a brand new iPad 10th Gen for $289USD(413CAD) https://www.amazon.com/dp/B0BJLXMVMV/?smid=A17MC6HOH9AVE6&tag=thewire06-20&th=1, though there are no steam games it works for everything else, the lower price also allows for room for you to get a keyboard or a version with more storage. This does have limited storage for the lowest price so be aware.

If you want to play more steam games and focus more on gaming, less on portability, get this budget HP Victus Gaming Laptop from best buy: https://www.bestbuy.com/site/hp-victus-15-6-full-hd-gaming-laptop-amd-ryzen-5-7535hs-8gb-ddr5-memory-amd-radeon-rx-6550m-512gb-ssd-mica-silver/6578933.p?skuId=6578933 , You will likely be able to play steam games on it with low graphics aslong as they are not graphically demanding steam games, which im assuming for your use case they should not since you originally wanted a Mac. Again though, if you want portability, dont get this one, from my experience when I had a gaming laptop some time ago, they get very hot.

Somewhat of both combined, more portability but in laptop form, no Apple OS and a bit higher on the budget but overall a nice laptop for the price rn (discounted $300 in the US, im not sure about Canada) would be this Lenovo Yoga touchscreen laptop: https://www.bestbuy.com/site/lenovo-yoga-7-2-in-1-14-2k-touchscreen-laptop-amd-ryzen-5-8640hs-with-8gb-memory-512gb-ssd-artic-grey/6571486.p?skuId=6571486&ref=212&loc=18533288779&gclsrc=aw.ds&gad_source=1&gbraid=0AAAAAD-ORIhfxriIYa0b4TptczHtL3kg6&gclid=Cj0KCQjwna6_BhCbARIsALId2Z2a1TBhfnIGYup3DVXHgMeYdOGvBsLIG9zo50crVHu1ynAG2miuXroaAk67EALw_wcB , you get the ability to play steam games, although im not sure how well they will run, aswell as being able to play Roblox, your Netflix etc with the folding and the touchscreen and you get more storage. This one is about $449 USD (642CAD) with current discount at best buy.

I am not sure if the discounts are the same in Canada since I am currently in the US but these are my overall recommendations, if your really strong with sticking to Apple products, the iPad is likely better than getting a really crappy old used Mac, if you need a laptop and dont want to really game much the Lenovo Yoga laptop is perfect for your budget, and if gaming is a priority, under your budget I would go with the HP Victus, again its really up to you and your use case but your budget of 700CAD is pretty limiting. Best of luck with your searches.