If you want to start with something simple, take a look at http://forum.mikrotik.com/t/using-routeros-to-qos-your-network-2020-edition/66683/252 This is for fq_codel. I’ve been using that configuration with very good results for some time now. My connection is 120/12, so I’m not losing too much by going 118/11.
If you want to try CAKE, I posted a few examples here: http://forum.mikrotik.com/t/some-quick-comments-on-configuring-cake/152505/255 But in all my tests on hAP ac2 and a cable Internet connection fq_codel gave better results than CAKE. Perhaps for a per-host isolation CAKE would be better, especially if you have a lot of client devices, since fq_codel works on flows (1024 by default) regardless of what host they belong to.
The approach above is not using packet marks, so it’s very easy to configure. It also allows to have fasttrack enabled. Depending on your Internet bandwidth you might not need fasttrack at all, but why not have it when there is such an option? If you use wireless on hAP ac2 (I don’t), then you will likely want fasttrack as wireless takes plenty of CPU.