New to networking. What all do I need to do to start using my HEX S as a simple router? I want to use the SFP port as my Internet In and the rest to go to my 3 TP-Link Access Points and computers..
Reset to defaults (if it is not), upgrade to latest stable (currently V7.16.1 assuming you are also running V7) and that is it!
https://help.mikrotik.com/docs/display/ROS/Reset+Button
https://help.mikrotik.com/docs/display/ROS/Upgrading+and+installation
Reset to factory default (if not already done).
And off you go …
If you want more detailed answers, you need to provide more details on what you plan to do.
EDIT: great minds etc etc … 
EDIT2: not nice to edit initial post when already 2 answers have been given …
If starting from scratch suggest watching beginner videos on youtube… just put beginner mikrotik and lots of good stuff comes up.
No point in telling you do stuff where you have zero understanding and just copy and paste.
Thanks. Is this router more powerful or faster than the TP-Link ER605v2 that I am using now?
Looking at test results/specifcations, I don’t think so.
That TP link would be a bit better (but not much).
The TP-Link ER605v2 uses the exact same chip as the hEX S, namely MediaTek MT7621A. Which means, with fewer available features and flexibility, the TP-Link one should have better performance than the hEX S. The MT7621A chip has full hardware acceleration for NAT and L3 that can be used by other router manufacturers, including OperWRT, but not by RouterOS. On other devices using this chip 9xx Mbps NAT is doable with almost no CPU utilization, but on the hEX S you need fasttrack (which is software) to reach the same number and CPU usage is much higher. On RouterOS only hardware L2 is usable for this chip.
The problem with watching YouTube videos as beginner guide to RouterOS is that most of them are either outdated, missing something, or outright dangerous because they completely omit the firewall config for instance. Someone with no experiences won’t be able to choose the right video and will end up with WinBox exposed on the internet. It’s much better to start with the default configuration, use QuickSet once to configure the WAN and set the LAN IP. He then can study the default configuration and start learning from that.
Sounds like good advice to me. Thanks for the info!
What would be a good step up for a wired router?