Need Wi-Fi solution for house and nearby warehouses

There are professional companies that can help you with solutions or installation if you want.
One possible solution is to have a PoE capable switch installed close to your preferred internet line and then have structured cabling to a number of access points. Connect the upstream port of the switch to your internet (VPN) router.

I recommend making the internet router your DHCP server so that as clients move between access points they don't need to renegotiate their connection to the network, which will make for less risk of being dropped.

Which switch to choose depends on the number of PoE devices you want to attach and the PoE power budget they will need. For example, this will also enable PoE enabled cameras if you want. The only thing to watch is the length of the network cable you need to use as Cat 6, for example, supports up to 100 meters from access point to PoE switch (including patch panel cable).
The choice of access point (WAX610, WAX610Y, WAX620, WAX630) will depend on how many clients (devices, computers, mobile phones, etc) that are estimated to connect at the same time and how much speed you want. How many access points you will need will depend on number of clients, density of walls and other equipment that might interfere with the signal, and overall physical coverage you will need to support. I believe there are a number of software packages available that can help with planning access point heat maps if you need it.

The WAX series of access points will allow you to have a single SSID or multiple SSID's, handy if you want to give guests or specific hardware internet access without giving others access to your other connected equipment. For example, it will allow you to connect stuff at your home on a SSID but not allow clients connecting in the warehouse access to your home network connected gear. You can also throttle certain SSID speeds if you want, like not allow guests to saturate your main internet connection.