I've heard great things about TP-Link's switches (even for home networks) so I opted to get the TL-SG108E and TL-SG2008 switches.  I'm planning on using the TL-SG2008 switch as almost a Layer 3 intermediary device, with the TL-SG108E L2 switches connected to the actual end devices and "dumb" switches (a different brand). 

I'm very much new to having equipment of my own and decided to get business switches partly because I'm planning to take my CCNA in six months and so I thought that exposure to actual hardware and having a stake in it (literally the portion of my network over ethernet) would be challenging, but fun as well, and it has been.  

So my challenges so far have been the fact that I cannot have a wire connect my (currently two) TL-SG108E switches without taking down one branch of my "ethernetwork" associated with one of the switches, while taking that wire out simply restored everything back to working order.  Also, this may have been a rookie mistake, but I attempted to connect two different ethernet connections between the TL-SG2008 and my ISP gateway, so I want to just make sure that there isn't anything actually wrong with my switches since, though I kept the boxes, I really don't want to have to return anything.

My vision for my network is to have around four VLANs (my office, general, bedroom, and downstairs office) for the TL-SG2008 switch (I currently have two of them set since I only have two of the TL-SG108E switches so far) while I want each switch to be configured to have different VLANs of their own (which I somewhat have configured in the two that I have), but I'm just afraid of connecting the switches together again.

I'm also hoping for any recommendations on access points and routers as, while I would get the Omada APs and VPN router, I've read that the home DECO mesh network routers (that I know can be used as access points as well) and the home AX routers may be the best options for me simply because I want to only deal with one ethernet cable between the gateway/router and the main AP hub, while I need ethernet backhaul to the downstairs office and my parents' closet (where the former homeowners placed the server rack), and I would also like to ensure that a router that I get can be configured with the VPN that I already use (Surfshark).

The overall goal of this is to build a home/small business network that allows my father (whose home office is downstairs in our sunroom that's technically outside of the house) to use his VoIP service and connect to ethernet, allows me to get ethernet at my various workstations (I'm trying to start up my business and also work full-time), while simultaneously getting better WiFi in general (I have my gateway on one side of the house near my office, but my bedroom and my parents' bedroom are on the other side, which is why I have a mess of cables wired to this side of the house upstairs - I own the house so I took the liberty of justifying to my mother exactly why I need this formerly ugly set of cables lol).  While I know where to start, I don't know the way forward, both to alleviate some of those issues that I outlined and to build up and complete this network (for now at least).

Any help towards that goal would be much appreciated, thank you!