Hi,
I understand your requirement and based on the same I'm proposing you for the solution at my level best.
I have more then 7 years of experience in Network and Server administration, where I have worked for 4 major MNC's to deliver same kind and higher level of solutions/designs to achieve the scenario. Also I worked on multi-vendor devices like Fortinet(3040B,200D, 600D, 800C, 20D, etc) HP (MSR50-40, 20-11,50-60, A7500, 5500,A1000E,etc), CISCO (ASA 5000 series, 1841,7200, 1900,4500 Catalyst, Nexus 5K,7K,2K and 1K,etc), PALO ALTO, Check Point etc and technologies(VPN, BGP, EIGRP, OSPF,RIPv2,MSTP, VLAN, VTP, etc).Hopefully I can give you the quality of work and positive result in your project.
As you mentioned in your project description that "Laptop/PC are able to go the internet. Guest device such as Smartphone and Laptop are on different network (don't know what it calls) and not able to connect to Intranet or network drive in the local Network" can be achieve by configuring/making some changes (Routing/ Security policies) on router and firewall.
For further clarification we need to have joint discussion, in that we can clarify our query/doubt.
Hope I'll hear a positive response from you.
Thanks
Biplab