I think you need to be more honest and clear with your requirements.
You speak of switch on one hand and then talk about old pfsense router.
Then you speak more about switch and vlans and then talk handling VPN.
So you need to get your story straight.
Be advised you are buying a primarily designed switch but with mikrotik RoS you get a fully capable routing capability albeit, reduced throughput in routing mode as its designed for high speed switching.
Regardless, this is the bible to setup the MT device for vlans: Using RouterOS to VLAN your network
If you are using the device solely as a switch then this is a decent vid:
https://www.youtube.com/watch?v=YLtGQAQ8iS0
What is the throughput of your WAN connection??