In browser http://192.168.88.1 or with WinBox tool for Windows

WebFig tab

Set Interface for WAN
All interfaces for LAN have to be in bridge incl. the WLAN if such (excl. the WAN interface)
Under IP - DHCP Client  set the WAN interface
Under IP - DHCP Server  set the bridge 

Under System Users - set some uder with full permissions and remove the default admin user (for security)

FireWall

If you're needing to support, or would like others to support your Mikrotik set up remotely, as well as allowing access through any Firewall you might have over a connection, you would need to make the following changes in the Routerboard Winbox set up:

 

    On the Right hand menu Select IP  - Firewall, and Filter Rules.
    Click the + to add a new rule.
    Change Chain to input.
    Change Protocol to tcp.
    Change Dst. Port to 8291.
    On the Action tab and make sure Action is set to accept.
    Create a name for this rule in Comment such as “winbox” (to easily identify this)
    Click OK.

    NB: The RouterOS runs through the Filter Rules in order, so you need to drag and drop this new rule above the last “drop” rule for this to work.


 Under Files Backup to make or load from backup setup.