GS308E VLAN to separate home devices

There is much more required I'm afraid.

Technically, 802.1q VLANs make up individual isolated networks, each needs it's own IP subnet, default gateway, DHCP server. Granted, a capable small business class router might fit here.

If you have some network cabling in the house and want to carry multiple VLANs over trunks, all switches in the rooms need to be VLAN capable, and need to be configured accordingly.

To make the VLANs communicate in a controlled way - to start with just TCP/IP and four VLANs and subnets - you either need a capable router able to deal with the bandwidth, or a advanced switch with L3 functionality.

Technically, "big" OS like Windows, MacOS or Linux can "print" or access a NAS (using the SMB protocol) over the plain IP address. Other platforms like iOS or Android or the likes need Apps - most of these depend on the ability to discover, being by Bonjour (limited to a single subnet), UPnP SSDP like the NAS SMB announcement (Multicast based, requires a capable forwarder to distribute announcement). Otherwise no NAS access, no printing from any device, ... The convenience of a discovery does - because many systems still depend on other mechanisms, typically various versions of broadcast .. which does never leave the subnet (and the VLAN therefore).

Even more difficult is the IoT story. Of course, IoT depending _only_ on an Internet service can be put into an own VLAN, permitting Internet only - that's what these odd IoT security theories imply. Trouble starts if mobile phones, tablets, controllers are used for the discovery, the initial installation, the later installation, and then for the daily operations. Say some fancy IP power switches can't really be used over the Internet - the latency would be much to high, and the dependency on the Internet availability is killing the idea. Read for example no way to switch on the lights over the Internet. And if you put your family members mobile phones, tablets and then the IoT into different VLANs ... they will unlikely to discover the controllers or IoTs in another VLAN.

Your consumer class router des not support more then one network, the so called "guest network" is a pure L2+ implementation on the same network and for the WiFi only - on the very same IP subnet - no VLAN at all. 

And when complex IoT like media players, IPTV, VoIP, and much more will be added - the complexity will grow massively because of IGMP Multicast and QoS comes into the play - you don't want the live TV video stream flow out all LAN ports and WLAN SSIDs. 

Said that: You need much more than "just" a simple L2 VLAN capable switch for your project. Reality will bring you quickly back to have different device "classes" into your "main" VLAN. 

Even if you are very experienced in networking (I'd say "hardcore networking") and willing to spend a lot of time and effort ... your results will vary.

Good luck with your project!