Try reading some helpful resources. If you’re fast learner, there’s manual with some helpful examples. You can look at this one:
and also the following one, and it should give you some ideas. Focus on the part how vlans are defined, type (tagged/untagged), number, port, and how you assign IP subnet to different vlans (that’s in example #3).
If that’s not enough, there’s also this popular and very detailed thread: Using RouterOS to VLAN your network