What if you don’t trust the pcs in the LAN?

My landlord premits internet access through his phone company wireless/optic cable modem. He and his wife aren’t concerned about internet security because they only word process. My laptop gets bombarded with contaminations from their pc because we share the LAN. My question is: can I isolate my laptop on my own subnet and still have internet? I have a switch and a wireless router in storage, and probably a gateway somewhere.