I've asked if I could continue working from home. They said ok. The laptop belongs to the company with VPN on it. From home I'll connect the laptop to my personal network/rooter with wifi. When I'll deliver the laptop I'll change my personal/home wifi password. Is there any other security concerns for my home network while I am connected to the office VPN? They can see other devices of mine? Should I worry for something? They (the IT administrators) can access my home network?
Is there any other security concerns for my home network while I am connected to the office VPN
Someone from IT department of your work who wishes to gather info on your home network can do that using your laptop. (though this is so risky, you wouldn't believe the legal complications if you'll find out that)
They can see other devices of mine?
ARP, packet broadcasting, etc makes it easy to collect information passively.
Should I worry for something?
Unless someone took a personal interest of you, or there some kind of maniac trying to stalk you, no.
They (the IT administrators) can access my home network?
Peculiar question. Network, yes. Shared files over the home network, yes. Sniff your traffic, yes. Get your wifi password, easily. Send something malicious to other devices, sure.
Guest mode, Access list, separated VLAN, whatever segmentation or control features your router have, you can use to segment your work laptop from home devices.
Sure, most VPNs are implemented as a virtual network interface and some routing rules to route all network traffic to it. The physical network interface is still there and an IT admin could bypass the VPN's routing rules to send traffic to your home network if they really wanted to.
If you're really paranoid that your company's IT department is out to get you, then you can turn on the Guest Mode on your home router and put your work laptop on that so that it can't see any other devices on your home network. Personally I do the opposite: put all my "smart home" junk on the Guest network to prevent them from finding my work laptop.