Well I use Winbox and terminal
Best is to get familiar with them.
First thing I would do is have a read through this link and start there.
https://wiki.mikrotik.com/wiki/Manual:S ... our_Router
As for setup...........................
You need to define the following..........
/interface ethernet
/interface bridge ( I would put my NAS LAN on the bridge, the rest not).
/interface list
/ip pool
/ip dhcp-server
/interface bridge port (where you assign ether interfaces to bridge in this case if ether5 is your wan port and ether1 is your NAS Lan, it would be solely ether1)
/interface list member (where you define which interfaces are on the LAN or WAN.
/ip address (dont worry about the WAN one, just enter in the LAN ones - except if its a static IP and you have all the numbers)
/ip dhcp-client
/ip dhcp-server network (seems redundant but every item is entered in separately when building subnets.)
/ip dns
/ip firewall address-list (for now at least identify which PCs ;you will use to administer the router internally (or perhaps one subnet).
/ip firewall filter (the default rules plust the link above will get you going)
/ip firewall NAT
(you need to ensure private to public and back to private transation when users go out to the net - source nat)
(you need to detail any planned incoming unsolicited traffic - destnation nat)
/ip route (perhaps the trickiest part of the setup but basically you have one WAN so its not so bad)
/ip service (as per the link above turn everything off except winbox and ssh and change ssh port to non-standard)
/ip ssh set to strong crypto
/ip DNS (as required/desired)
The terminal selection on winbox is where you can do commands manually.
The most useful one is to see the configuration in text form.
Type
/export hide-sensitive file=nameofyourchoice
After that you go to the FILES selection on the menu and you will see that file there.
Right click and download to your PC and use notepad++ to view.
Chances are you will want to post it in a thread when you wish to see what you have done right and wrong.
Dont forget to delete the file from FILES after you download it.
The other nice thing about the configuration exported is you can modify any part of the text file and then simply paste that bit of revision into TERMINAL and it will add the change to your router
There is tons to learn, take it slow. If you know networking, unlike me, it will go much smoother.