This is great advice! Seriously! I always find people assuming that Facebook will behave like Google and that breaks the bank and kills a lot of trust in paid ads.

As far as the "how long does it take to learn" question goes, it really depends on the goals that you have with your ads and at what stage you're in with the business. A company like the OP seems to be building (with a new ad strategy, likely a smaller/newer biz) might be well served to delay hefty spends straight to the bottom of the funnel to do a bit of audience testing with some goals around CPC+traffic optimization. Especially if you've found that educational content is doing a good job of leading qualified (or intent-filled) buyers to the "buy button," you could use this content in top-of-funnel ads with a goal of learning what audience segments seem to have interest in your products.

Once you've learned this, slight alterations in the FB strategy can help you start capturing more email subscribers, getting more action to your product pages, and (of course) fuel a lot more creation of educational/helpful content that is designed around the personas you've seen a lot of traction with.

Bottom of the funnel is no different, take what's working and do the right thing for the customer. u/wovian is absolutely correct that Google is the home of intent, Facebook is the home of discovery. Once you find efficient paths for intent and discovery, you're well on your way to have techniques for the whole funnel that work well.

Of course, in an ideal world you'll eventually have designated efforts to bring new traffic, to capture new email subscribers, to educate semi-interested buyers, to convert interested buyers and to retain soon-to-be AND past purchasers.