Achievements?

Hi everyone! Iā€™m so psyched because Iā€™ve been with FB for several years but I just got a 3 month Plus Pass! Iā€™ve been looking at all the features and am so excited!

So how exactly do the Achievements work? Does anyone have any tips about them or can explain a bit?

If not, itā€™s ok Iā€™ll also look around at everything some more :).

Ps Iā€™m starting the 2 week Strong Runner Challenge on Thursday and canā€™t wait!